go-mail/msg.go

1415 lines
43 KiB
Go

// SPDX-FileCopyrightText: 2022-2023 The go-mail Authors
//
// SPDX-License-Identifier: MIT
package mail
import (
"bytes"
"context"
"crypto/rsa"
"crypto/x509"
"embed"
"errors"
"fmt"
ht "html/template"
"io"
"mime"
"net/mail"
"os"
"os/exec"
"path/filepath"
"strings"
"syscall"
tt "text/template"
"time"
)
var (
// ErrNoFromAddress should be used when a FROM address is requrested but not set
ErrNoFromAddress = errors.New("no FROM address set")
// ErrNoRcptAddresses should be used when the list of RCPTs is empty
ErrNoRcptAddresses = errors.New("no recipient addresses set")
)
const (
// errTplExecuteFailed is issued when the template execution was not successful
errTplExecuteFailed = "failed to execute template: %w"
// errTplPointerNil is issued when a template pointer is expected but it is nil
errTplPointerNil = "template pointer is nil"
// errParseMailAddr is used when a mail address could not be validated
errParseMailAddr = "failed to parse mail address %q: %w"
)
const (
// NoPGP indicates that a message should not be treated as PGP encrypted
// or signed and is the default value for a message
NoPGP PGPType = iota
// PGPEncrypt indicates that a message should be treated as PGP encrypted
// This works closely together with the corresponding go-mail-middleware
PGPEncrypt
// PGPSignature indicates that a message should be treated as PGP signed
// This works closely together with the corresponding go-mail-middleware
PGPSignature
)
// MiddlewareType is the type description of the Middleware and needs to be returned
// in the Middleware interface by the Type method
type MiddlewareType string
// Middleware is an interface to define a function to apply to Msg before sending
type Middleware interface {
Handle(*Msg) *Msg
Type() MiddlewareType
}
// PGPType is a type alias for a int representing a type of PGP encryption
// or signature
type PGPType int
// Msg is the mail message struct
type Msg struct {
// addrHeader is a slice of strings that the different mail AddrHeader fields
addrHeader map[AddrHeader][]*mail.Address
// attachments represent the different attachment File of the Msg
attachments []*File
// boundary is the MIME content boundary
boundary string
// charset represents the charset of the mail (defaults to UTF-8)
charset Charset
// embeds represent the different embedded File of the Msg
embeds []*File
// encoder represents a mime.WordEncoder from the std lib
encoder mime.WordEncoder
// encoding represents the message encoding (the encoder will be a corresponding WordEncoder)
encoding Encoding
// genHeader is a slice of strings that the different generic mail Header fields
genHeader map[Header][]string
// isDelivered signals if a message has been delivered or not
isDelivered bool
// middlewares is the list of middlewares to apply to the Msg before sending in FIFO order
middlewares []Middleware
// mimever represents the MIME version
mimever MIMEVersion
// parts represent the different parts of the Msg
parts []*Part
// preformHeader is a slice of strings that the different generic mail Header fields
// of which content is already preformated and will not be affected by the automatic line
// breaks
preformHeader map[Header]string
// pgptype indicates that a message has a PGPType assigned and therefore will generate
// different Content-Type settings in the msgWriter
pgptype PGPType
// sendError holds the SendError in case a Msg could not be delivered during the Client.Send operation
sendError error
// noDefaultUserAgent indicates whether the default User Agent will be excluded for the Msg when it's sent.
noDefaultUserAgent bool
// SMime represents a middleware used to sign messages with S/MIME
sMime *SMime
}
// SendmailPath is the default system path to the sendmail binary
const SendmailPath = "/usr/sbin/sendmail"
// MsgOption returns a function that can be used for grouping Msg options
type MsgOption func(*Msg)
// NewMsg returns a new Msg pointer
func NewMsg(opts ...MsgOption) *Msg {
msg := &Msg{
addrHeader: make(map[AddrHeader][]*mail.Address),
charset: CharsetUTF8,
encoding: EncodingQP,
genHeader: make(map[Header][]string),
preformHeader: make(map[Header]string),
mimever: MIME10,
}
// Override defaults with optionally provided MsgOption functions
for _, option := range opts {
if option == nil {
continue
}
option(msg)
}
// Set the matcing mime.WordEncoder for the Msg
msg.setEncoder()
return msg
}
// WithCharset overrides the default message charset
func WithCharset(c Charset) MsgOption {
return func(m *Msg) {
m.charset = c
}
}
// WithEncoding overrides the default message encoding
func WithEncoding(e Encoding) MsgOption {
return func(m *Msg) {
m.encoding = e
}
}
// WithMIMEVersion overrides the default MIME version
func WithMIMEVersion(mv MIMEVersion) MsgOption {
return func(m *Msg) {
m.mimever = mv
}
}
// WithBoundary overrides the default MIME boundary
func WithBoundary(b string) MsgOption {
return func(m *Msg) {
m.boundary = b
}
}
// WithMiddleware add the given middleware in the end of the list of the client middlewares
func WithMiddleware(mw Middleware) MsgOption {
return func(m *Msg) {
m.middlewares = append(m.middlewares, mw)
}
}
// WithPGPType overrides the default PGPType of the message
func WithPGPType(pt PGPType) MsgOption {
return func(m *Msg) {
m.pgptype = pt
}
}
// WithNoDefaultUserAgent configures the Msg to not use the default User Agent
func WithNoDefaultUserAgent() MsgOption {
return func(m *Msg) {
m.noDefaultUserAgent = true
}
}
// SignWithSMime configures the Msg to be signed with S/MIME
func (m *Msg) SignWithSMime(privateKey *rsa.PrivateKey, certificate *x509.Certificate) error {
sMime, err := NewSMime(privateKey, certificate)
if err != nil {
return err
}
m.sMime = sMime
return nil
}
// SetCharset sets the encoding charset of the Msg
func (m *Msg) SetCharset(c Charset) {
m.charset = c
}
// SetEncoding sets the encoding of the Msg
func (m *Msg) SetEncoding(e Encoding) {
m.encoding = e
m.setEncoder()
}
// SetBoundary sets the boundary of the Msg
func (m *Msg) SetBoundary(b string) {
m.boundary = b
}
// SetMIMEVersion sets the MIME version of the Msg
func (m *Msg) SetMIMEVersion(mv MIMEVersion) {
m.mimever = mv
}
// SetPGPType sets the PGPType of the Msg
func (m *Msg) SetPGPType(t PGPType) {
m.pgptype = t
}
// Encoding returns the currently set encoding of the Msg
func (m *Msg) Encoding() string {
return m.encoding.String()
}
// Charset returns the currently set charset of the Msg
func (m *Msg) Charset() string {
return m.charset.String()
}
// SetHeader sets a generic header field of the Msg
// For adding address headers like "To:" or "From", see SetAddrHeader
//
// Deprecated: This method only exists for compatibility reason. Please use SetGenHeader instead
func (m *Msg) SetHeader(header Header, values ...string) {
m.SetGenHeader(header, values...)
}
// SetGenHeader sets a generic header field of the Msg
// For adding address headers like "To:" or "From", see SetAddrHeader
func (m *Msg) SetGenHeader(header Header, values ...string) {
if m.genHeader == nil {
m.genHeader = make(map[Header][]string)
}
for i, val := range values {
values[i] = m.encodeString(val)
}
m.genHeader[header] = values
}
// SetHeaderPreformatted sets a generic header field of the Msg which content is
// already preformated.
//
// Deprecated: This method only exists for compatibility reason. Please use
// SetGenHeaderPreformatted instead
func (m *Msg) SetHeaderPreformatted(header Header, value string) {
m.SetGenHeaderPreformatted(header, value)
}
// SetGenHeaderPreformatted sets a generic header field of the Msg which content is
// already preformated.
//
// This method does not take a slice of values but only a single value. This is
// due to the fact, that we do not perform any content alteration and expect the
// user has already done so
//
// **Please note:** This method should be used only as a last resort. Since the
// user is respondible for the formating of the message header, go-mail cannot
// guarantee the fully compliance with the RFC 2822. It is recommended to use
// SetGenHeader instead.
func (m *Msg) SetGenHeaderPreformatted(header Header, value string) {
if m.preformHeader == nil {
m.preformHeader = make(map[Header]string)
}
m.preformHeader[header] = value
}
// SetAddrHeader sets an address related header field of the Msg
func (m *Msg) SetAddrHeader(header AddrHeader, values ...string) error {
if m.addrHeader == nil {
m.addrHeader = make(map[AddrHeader][]*mail.Address)
}
var addresses []*mail.Address
for _, addrVal := range values {
address, err := mail.ParseAddress(addrVal)
if err != nil {
return fmt.Errorf(errParseMailAddr, addrVal, err)
}
addresses = append(addresses, address)
}
switch header {
case HeaderFrom:
if len(addresses) > 0 {
m.addrHeader[header] = []*mail.Address{addresses[0]}
}
default:
m.addrHeader[header] = addresses
}
return nil
}
// SetAddrHeaderIgnoreInvalid sets an address related header field of the Msg and ignores invalid address
// in the validation process
func (m *Msg) SetAddrHeaderIgnoreInvalid(header AddrHeader, values ...string) {
var addresses []*mail.Address
for _, addrVal := range values {
address, err := mail.ParseAddress(m.encodeString(addrVal))
if err != nil {
continue
}
addresses = append(addresses, address)
}
m.addrHeader[header] = addresses
}
// EnvelopeFrom takes and validates a given mail address and sets it as envelope "FROM"
// addrHeader of the Msg
func (m *Msg) EnvelopeFrom(from string) error {
return m.SetAddrHeader(HeaderEnvelopeFrom, from)
}
// EnvelopeFromFormat takes a name and address, formats them RFC5322 compliant and stores them as
// the envelope FROM address header field
func (m *Msg) EnvelopeFromFormat(name, addr string) error {
return m.SetAddrHeader(HeaderEnvelopeFrom, fmt.Sprintf(`"%s" <%s>`, name, addr))
}
// From takes and validates a given mail address and sets it as "From" genHeader of the Msg
func (m *Msg) From(from string) error {
return m.SetAddrHeader(HeaderFrom, from)
}
// FromFormat takes a name and address, formats them RFC5322 compliant and stores them as
// the From address header field
func (m *Msg) FromFormat(name, addr string) error {
return m.SetAddrHeader(HeaderFrom, fmt.Sprintf(`"%s" <%s>`, name, addr))
}
// To takes and validates a given mail address list sets the To: addresses of the Msg
func (m *Msg) To(rcpts ...string) error {
return m.SetAddrHeader(HeaderTo, rcpts...)
}
// AddTo adds an additional address to the To address header field
func (m *Msg) AddTo(rcpt string) error {
return m.addAddr(HeaderTo, rcpt)
}
// AddToFormat takes a name and address, formats them RFC5322 compliant and stores them as
// as additional To address header field
func (m *Msg) AddToFormat(name, addr string) error {
return m.addAddr(HeaderTo, fmt.Sprintf(`"%s" <%s>`, name, addr))
}
// ToIgnoreInvalid takes and validates a given mail address list sets the To: addresses of the Msg
// Any provided address that is not RFC5322 compliant, will be ignored
func (m *Msg) ToIgnoreInvalid(rcpts ...string) {
m.SetAddrHeaderIgnoreInvalid(HeaderTo, rcpts...)
}
// ToFromString takes and validates a given string of comma separted
// mail address and sets them as To: addresses of the Msg
func (m *Msg) ToFromString(rcpts string) error {
return m.To(strings.Split(rcpts, ",")...)
}
// Cc takes and validates a given mail address list sets the Cc: addresses of the Msg
func (m *Msg) Cc(rcpts ...string) error {
return m.SetAddrHeader(HeaderCc, rcpts...)
}
// AddCc adds an additional address to the Cc address header field
func (m *Msg) AddCc(rcpt string) error {
return m.addAddr(HeaderCc, rcpt)
}
// AddCcFormat takes a name and address, formats them RFC5322 compliant and stores them as
// as additional Cc address header field
func (m *Msg) AddCcFormat(name, addr string) error {
return m.addAddr(HeaderCc, fmt.Sprintf(`"%s" <%s>`, name, addr))
}
// CcIgnoreInvalid takes and validates a given mail address list sets the Cc: addresses of the Msg
// Any provided address that is not RFC5322 compliant, will be ignored
func (m *Msg) CcIgnoreInvalid(rcpts ...string) {
m.SetAddrHeaderIgnoreInvalid(HeaderCc, rcpts...)
}
// CcFromString takes and validates a given string of comma separted
// mail address and sets them as Cc: addresses of the Msg
func (m *Msg) CcFromString(rcpts string) error {
return m.Cc(strings.Split(rcpts, ",")...)
}
// Bcc takes and validates a given mail address list sets the Bcc: addresses of the Msg
func (m *Msg) Bcc(rcpts ...string) error {
return m.SetAddrHeader(HeaderBcc, rcpts...)
}
// AddBcc adds an additional address to the Bcc address header field
func (m *Msg) AddBcc(rcpt string) error {
return m.addAddr(HeaderBcc, rcpt)
}
// AddBccFormat takes a name and address, formats them RFC5322 compliant and stores them as
// as additional Bcc address header field
func (m *Msg) AddBccFormat(name, addr string) error {
return m.addAddr(HeaderBcc, fmt.Sprintf(`"%s" <%s>`, name, addr))
}
// BccIgnoreInvalid takes and validates a given mail address list sets the Bcc: addresses of the Msg
// Any provided address that is not RFC5322 compliant, will be ignored
func (m *Msg) BccIgnoreInvalid(rcpts ...string) {
m.SetAddrHeaderIgnoreInvalid(HeaderBcc, rcpts...)
}
// BccFromString takes and validates a given string of comma separted
// mail address and sets them as Bcc: addresses of the Msg
func (m *Msg) BccFromString(rcpts string) error {
return m.Bcc(strings.Split(rcpts, ",")...)
}
// ReplyTo takes and validates a given mail address and sets it as "Reply-To" addrHeader of the Msg
func (m *Msg) ReplyTo(addr string) error {
replyTo, err := mail.ParseAddress(addr)
if err != nil {
return fmt.Errorf("failed to parse reply-to address: %w", err)
}
m.SetGenHeader(HeaderReplyTo, replyTo.String())
return nil
}
// ReplyToFormat takes a name and address, formats them RFC5322 compliant and stores them as
// the Reply-To header field
func (m *Msg) ReplyToFormat(name, addr string) error {
return m.ReplyTo(fmt.Sprintf(`"%s" <%s>`, name, addr))
}
// addAddr adds an additional address to the given addrHeader of the Msg
func (m *Msg) addAddr(header AddrHeader, addr string) error {
var addresses []string
for _, address := range m.addrHeader[header] {
addresses = append(addresses, address.String())
}
addresses = append(addresses, addr)
return m.SetAddrHeader(header, addresses...)
}
// Subject sets the "Subject" header field of the Msg
func (m *Msg) Subject(subj string) {
m.SetGenHeader(HeaderSubject, subj)
}
// SetMessageID generates a random message id for the mail
func (m *Msg) SetMessageID() {
hostname, err := os.Hostname()
if err != nil {
hostname = "localhost.localdomain"
}
randNumPrimary, _ := randNum(100000000)
randNumSecondary, _ := randNum(10000)
randString, _ := randomStringSecure(17)
procID := os.Getpid() * randNumSecondary
messageID := fmt.Sprintf("%d.%d%d.%s@%s", procID, randNumPrimary, randNumSecondary,
randString, hostname)
m.SetMessageIDWithValue(messageID)
}
// SetMessageIDWithValue sets the message id for the mail
func (m *Msg) SetMessageIDWithValue(messageID string) {
m.SetGenHeader(HeaderMessageID, fmt.Sprintf("<%s>", messageID))
}
// SetBulk sets the "Precedence: bulk" and "X-Auto-Response-Suppress: All" genHeaders which are
// recommended for automated mails like OOO replies
// See: https://www.rfc-editor.org/rfc/rfc2076#section-3.9
// See also: https://learn.microsoft.com/en-us/openspecs/exchange_server_protocols/ms-oxcmail/ced68690-498a-4567-9d14-5c01f974d8b1#Appendix_A_Target_51
func (m *Msg) SetBulk() {
m.SetGenHeader(HeaderPrecedence, "bulk")
m.SetGenHeader(HeaderXAutoResponseSuppress, "All")
}
// SetDate sets the Date genHeader field to the current time in a valid format
func (m *Msg) SetDate() {
now := time.Now().Format(time.RFC1123Z)
m.SetGenHeader(HeaderDate, now)
}
// SetDateWithValue sets the Date genHeader field to the provided time in a valid format
func (m *Msg) SetDateWithValue(timeVal time.Time) {
m.SetGenHeader(HeaderDate, timeVal.Format(time.RFC1123Z))
}
// SetImportance sets the Msg Importance/Priority header to given Importance
func (m *Msg) SetImportance(importance Importance) {
if importance == ImportanceNormal {
return
}
m.SetGenHeader(HeaderImportance, importance.String())
m.SetGenHeader(HeaderPriority, importance.NumString())
m.SetGenHeader(HeaderXPriority, importance.XPrioString())
m.SetGenHeader(HeaderXMSMailPriority, importance.NumString())
}
// SetOrganization sets the provided string as Organization header for the Msg
func (m *Msg) SetOrganization(org string) {
m.SetGenHeader(HeaderOrganization, org)
}
// SetUserAgent sets the User-Agent/X-Mailer header for the Msg
func (m *Msg) SetUserAgent(userAgent string) {
m.SetGenHeader(HeaderUserAgent, userAgent)
m.SetGenHeader(HeaderXMailer, userAgent)
}
// IsDelivered will return true if the Msg has been successfully delivered
func (m *Msg) IsDelivered() bool {
return m.isDelivered
}
// RequestMDNTo adds the Disposition-Notification-To header to request a MDN from the receiving end
// as described in RFC8098. It allows to provide a list recipient addresses.
// Address validation is performed
// See: https://www.rfc-editor.org/rfc/rfc8098.html
func (m *Msg) RequestMDNTo(rcpts ...string) error {
var addresses []string
for _, addrVal := range rcpts {
address, err := mail.ParseAddress(addrVal)
if err != nil {
return fmt.Errorf(errParseMailAddr, addrVal, err)
}
addresses = append(addresses, address.String())
}
if _, ok := m.genHeader[HeaderDispositionNotificationTo]; ok {
m.genHeader[HeaderDispositionNotificationTo] = addresses
}
return nil
}
// RequestMDNToFormat adds the Disposition-Notification-To header to request a MDN from the receiving end
// as described in RFC8098. It allows to provide a recipient address with name and address and will format
// accordingly. Address validation is performed
// See: https://www.rfc-editor.org/rfc/rfc8098.html
func (m *Msg) RequestMDNToFormat(name, addr string) error {
return m.RequestMDNTo(fmt.Sprintf(`%s <%s>`, name, addr))
}
// RequestMDNAddTo adds an additional recipient to the recipient list of the MDN
func (m *Msg) RequestMDNAddTo(rcpt string) error {
address, err := mail.ParseAddress(rcpt)
if err != nil {
return fmt.Errorf(errParseMailAddr, rcpt, err)
}
var addresses []string
addresses = append(addresses, m.genHeader[HeaderDispositionNotificationTo]...)
addresses = append(addresses, address.String())
if _, ok := m.genHeader[HeaderDispositionNotificationTo]; ok {
m.genHeader[HeaderDispositionNotificationTo] = addresses
}
return nil
}
// RequestMDNAddToFormat adds an additional formated recipient to the recipient list of the MDN
func (m *Msg) RequestMDNAddToFormat(name, addr string) error {
return m.RequestMDNAddTo(fmt.Sprintf(`"%s" <%s>`, name, addr))
}
// GetSender returns the currently set envelope FROM address. If no envelope FROM is set it will use
// the first mail body FROM address. If useFullAddr is true, it will return the full address string
// including the address name, if set
func (m *Msg) GetSender(useFullAddr bool) (string, error) {
from, ok := m.addrHeader[HeaderEnvelopeFrom]
if !ok || len(from) == 0 {
from, ok = m.addrHeader[HeaderFrom]
if !ok || len(from) == 0 {
return "", ErrNoFromAddress
}
}
if useFullAddr {
return from[0].String(), nil
}
return from[0].Address, nil
}
// GetRecipients returns a list of the currently set TO/CC/BCC addresses.
func (m *Msg) GetRecipients() ([]string, error) {
var rcpts []string
for _, addressType := range []AddrHeader{HeaderTo, HeaderCc, HeaderBcc} {
addresses, ok := m.addrHeader[addressType]
if !ok || len(addresses) == 0 {
continue
}
for _, r := range addresses {
rcpts = append(rcpts, r.Address)
}
}
if len(rcpts) <= 0 {
return rcpts, ErrNoRcptAddresses
}
return rcpts, nil
}
// GetAddrHeader returns the content of the requested address header of the Msg
func (m *Msg) GetAddrHeader(header AddrHeader) []*mail.Address {
return m.addrHeader[header]
}
// GetAddrHeaderString returns the address string of the requested address header of the Msg
func (m *Msg) GetAddrHeaderString(header AddrHeader) []string {
var addresses []string
for _, mh := range m.addrHeader[header] {
addresses = append(addresses, mh.String())
}
return addresses
}
// GetFrom returns the content of the From address header of the Msg
func (m *Msg) GetFrom() []*mail.Address {
return m.GetAddrHeader(HeaderFrom)
}
// GetFromString returns the content of the From address header of the Msg as string slice
func (m *Msg) GetFromString() []string {
return m.GetAddrHeaderString(HeaderFrom)
}
// GetTo returns the content of the To address header of the Msg
func (m *Msg) GetTo() []*mail.Address {
return m.GetAddrHeader(HeaderTo)
}
// GetToString returns the content of the To address header of the Msg as string slice
func (m *Msg) GetToString() []string {
return m.GetAddrHeaderString(HeaderTo)
}
// GetCc returns the content of the Cc address header of the Msg
func (m *Msg) GetCc() []*mail.Address {
return m.GetAddrHeader(HeaderCc)
}
// GetCcString returns the content of the Cc address header of the Msg as string slice
func (m *Msg) GetCcString() []string {
return m.GetAddrHeaderString(HeaderCc)
}
// GetBcc returns the content of the Bcc address header of the Msg
func (m *Msg) GetBcc() []*mail.Address {
return m.GetAddrHeader(HeaderBcc)
}
// GetBccString returns the content of the Bcc address header of the Msg as string slice
func (m *Msg) GetBccString() []string {
return m.GetAddrHeaderString(HeaderBcc)
}
// GetGenHeader returns the content of the requested generic header of the Msg
func (m *Msg) GetGenHeader(header Header) []string {
return m.genHeader[header]
}
// GetParts returns the message parts of the Msg
func (m *Msg) GetParts() []*Part {
return m.parts
}
// GetAttachments returns the attachments of the Msg
func (m *Msg) GetAttachments() []*File {
return m.attachments
}
// GetBoundary returns the boundary of the Msg
func (m *Msg) GetBoundary() string {
return m.boundary
}
// SetAttachments sets the attachments of the message.
func (m *Msg) SetAttachments(files []*File) {
m.attachments = files
}
// SetAttachements sets the attachments of the message.
//
// Deprecated: use SetAttachments instead.
func (m *Msg) SetAttachements(files []*File) {
m.SetAttachments(files)
}
// UnsetAllAttachments unset the attachments of the message.
func (m *Msg) UnsetAllAttachments() {
m.attachments = nil
}
// GetEmbeds returns the embeds of the Msg
func (m *Msg) GetEmbeds() []*File {
return m.embeds
}
// SetEmbeds sets the embeds of the message.
func (m *Msg) SetEmbeds(files []*File) {
m.embeds = files
}
// UnsetAllEmbeds unset the embeds of the message.
func (m *Msg) UnsetAllEmbeds() {
m.embeds = nil
}
// UnsetAllParts unset the embeds and attachments of the message.
func (m *Msg) UnsetAllParts() {
m.UnsetAllAttachments()
m.UnsetAllEmbeds()
}
// SetBodyString sets the body of the message.
func (m *Msg) SetBodyString(contentType ContentType, content string, opts ...PartOption) {
buffer := bytes.NewBufferString(content)
writeFunc := writeFuncFromBuffer(buffer)
m.SetBodyWriter(contentType, writeFunc, opts...)
}
// SetBodyWriter sets the body of the message.
func (m *Msg) SetBodyWriter(
contentType ContentType, writeFunc func(io.Writer) (int64, error),
opts ...PartOption,
) {
p := m.newPart(contentType, opts...)
p.writeFunc = writeFunc
m.parts = []*Part{p}
}
// SetBodyHTMLTemplate sets the body of the message from a given html/template.Template pointer
// The content type will be set to text/html automatically
func (m *Msg) SetBodyHTMLTemplate(tpl *ht.Template, data interface{}, opts ...PartOption) error {
if tpl == nil {
return errors.New(errTplPointerNil)
}
buffer := bytes.Buffer{}
if err := tpl.Execute(&buffer, data); err != nil {
return fmt.Errorf(errTplExecuteFailed, err)
}
writeFunc := writeFuncFromBuffer(&buffer)
m.SetBodyWriter(TypeTextHTML, writeFunc, opts...)
return nil
}
// SetBodyTextTemplate sets the body of the message from a given text/template.Template pointer
// The content type will be set to text/plain automatically
func (m *Msg) SetBodyTextTemplate(tpl *tt.Template, data interface{}, opts ...PartOption) error {
if tpl == nil {
return errors.New(errTplPointerNil)
}
buf := bytes.Buffer{}
if err := tpl.Execute(&buf, data); err != nil {
return fmt.Errorf(errTplExecuteFailed, err)
}
writeFunc := writeFuncFromBuffer(&buf)
m.SetBodyWriter(TypeTextPlain, writeFunc, opts...)
return nil
}
// AddAlternativeString sets the alternative body of the message.
func (m *Msg) AddAlternativeString(contentType ContentType, content string, opts ...PartOption) {
buffer := bytes.NewBufferString(content)
writeFunc := writeFuncFromBuffer(buffer)
m.AddAlternativeWriter(contentType, writeFunc, opts...)
}
// AddAlternativeWriter sets the body of the message.
func (m *Msg) AddAlternativeWriter(
contentType ContentType, writeFunc func(io.Writer) (int64, error),
opts ...PartOption,
) {
part := m.newPart(contentType, opts...)
part.writeFunc = writeFunc
m.parts = append(m.parts, part)
}
// AddAlternativeHTMLTemplate sets the alternative body of the message to a html/template.Template output
// The content type will be set to text/html automatically
func (m *Msg) AddAlternativeHTMLTemplate(tpl *ht.Template, data interface{}, opts ...PartOption) error {
if tpl == nil {
return errors.New(errTplPointerNil)
}
buffer := bytes.Buffer{}
if err := tpl.Execute(&buffer, data); err != nil {
return fmt.Errorf(errTplExecuteFailed, err)
}
writeFunc := writeFuncFromBuffer(&buffer)
m.AddAlternativeWriter(TypeTextHTML, writeFunc, opts...)
return nil
}
// AddAlternativeTextTemplate sets the alternative body of the message to a text/template.Template output
// The content type will be set to text/plain automatically
func (m *Msg) AddAlternativeTextTemplate(tpl *tt.Template, data interface{}, opts ...PartOption) error {
if tpl == nil {
return errors.New(errTplPointerNil)
}
buffer := bytes.Buffer{}
if err := tpl.Execute(&buffer, data); err != nil {
return fmt.Errorf(errTplExecuteFailed, err)
}
writeFunc := writeFuncFromBuffer(&buffer)
m.AddAlternativeWriter(TypeTextPlain, writeFunc, opts...)
return nil
}
// AttachFile adds an attachment File to the Msg
func (m *Msg) AttachFile(name string, opts ...FileOption) {
file := fileFromFS(name)
if file == nil {
return
}
m.attachments = m.appendFile(m.attachments, file, opts...)
}
// AttachReader adds an attachment File via io.Reader to the Msg
//
// CAVEAT: For AttachReader to work it has to read all data of the io.Reader
// into memory first, so it can seek through it. Using larger amounts of
// data on the io.Reader should be avoided. For such, it is recommended to
// either use AttachFile or AttachReadSeeker instead
func (m *Msg) AttachReader(name string, reader io.Reader, opts ...FileOption) error {
file, err := fileFromReader(name, reader)
if err != nil {
return err
}
m.attachments = m.appendFile(m.attachments, file, opts...)
return nil
}
// AttachReadSeeker adds an attachment File via io.ReadSeeker to the Msg
func (m *Msg) AttachReadSeeker(name string, reader io.ReadSeeker, opts ...FileOption) {
file := fileFromReadSeeker(name, reader)
m.attachments = m.appendFile(m.attachments, file, opts...)
}
// AttachHTMLTemplate adds the output of a html/template.Template pointer as File attachment to the Msg
func (m *Msg) AttachHTMLTemplate(
name string, tpl *ht.Template, data interface{}, opts ...FileOption,
) error {
file, err := fileFromHTMLTemplate(name, tpl, data)
if err != nil {
return fmt.Errorf("failed to attach template: %w", err)
}
m.attachments = m.appendFile(m.attachments, file, opts...)
return nil
}
// AttachTextTemplate adds the output of a text/template.Template pointer as File attachment to the Msg
func (m *Msg) AttachTextTemplate(
name string, tpl *tt.Template, data interface{}, opts ...FileOption,
) error {
file, err := fileFromTextTemplate(name, tpl, data)
if err != nil {
return fmt.Errorf("failed to attach template: %w", err)
}
m.attachments = m.appendFile(m.attachments, file, opts...)
return nil
}
// AttachFromEmbedFS adds an attachment File from an embed.FS to the Msg
func (m *Msg) AttachFromEmbedFS(name string, fs *embed.FS, opts ...FileOption) error {
if fs == nil {
return fmt.Errorf("embed.FS must not be nil")
}
file, err := fileFromEmbedFS(name, fs)
if err != nil {
return err
}
m.attachments = m.appendFile(m.attachments, file, opts...)
return nil
}
// EmbedFile adds an embedded File to the Msg
func (m *Msg) EmbedFile(name string, opts ...FileOption) {
file := fileFromFS(name)
if file == nil {
return
}
m.embeds = m.appendFile(m.embeds, file, opts...)
}
// EmbedReader adds an embedded File from an io.Reader to the Msg
//
// CAVEAT: For EmbedReader to work it has to read all data of the io.Reader
// into memory first, so it can seek through it. Using larger amounts of
// data on the io.Reader should be avoided. For such, it is recommended to
// either use EmbedFile or EmbedReadSeeker instead
func (m *Msg) EmbedReader(name string, reader io.Reader, opts ...FileOption) error {
file, err := fileFromReader(name, reader)
if err != nil {
return err
}
m.embeds = m.appendFile(m.embeds, file, opts...)
return nil
}
// EmbedReadSeeker adds an embedded File from an io.ReadSeeker to the Msg
func (m *Msg) EmbedReadSeeker(name string, reader io.ReadSeeker, opts ...FileOption) {
file := fileFromReadSeeker(name, reader)
m.embeds = m.appendFile(m.embeds, file, opts...)
}
// EmbedHTMLTemplate adds the output of a html/template.Template pointer as embedded File to the Msg
func (m *Msg) EmbedHTMLTemplate(
name string, tpl *ht.Template, data interface{}, opts ...FileOption,
) error {
file, err := fileFromHTMLTemplate(name, tpl, data)
if err != nil {
return fmt.Errorf("failed to embed template: %w", err)
}
m.embeds = m.appendFile(m.embeds, file, opts...)
return nil
}
// EmbedTextTemplate adds the output of a text/template.Template pointer as embedded File to the Msg
func (m *Msg) EmbedTextTemplate(
name string, tpl *tt.Template, data interface{}, opts ...FileOption,
) error {
file, err := fileFromTextTemplate(name, tpl, data)
if err != nil {
return fmt.Errorf("failed to embed template: %w", err)
}
m.embeds = m.appendFile(m.embeds, file, opts...)
return nil
}
// EmbedFromEmbedFS adds an embedded File from an embed.FS to the Msg
func (m *Msg) EmbedFromEmbedFS(name string, fs *embed.FS, opts ...FileOption) error {
if fs == nil {
return fmt.Errorf("embed.FS must not be nil")
}
file, err := fileFromEmbedFS(name, fs)
if err != nil {
return err
}
m.embeds = m.appendFile(m.embeds, file, opts...)
return nil
}
// Reset resets all headers, body parts and attachments/embeds of the Msg
// It leaves already set encodings, charsets, boundaries, etc. as is
func (m *Msg) Reset() {
m.addrHeader = make(map[AddrHeader][]*mail.Address)
m.attachments = nil
m.embeds = nil
m.genHeader = make(map[Header][]string)
m.parts = nil
}
// ApplyMiddlewares apply the list of middlewares to a Msg
func (m *Msg) applyMiddlewares(msg *Msg) *Msg {
for _, middleware := range m.middlewares {
msg = middleware.Handle(msg)
}
return msg
}
// signMessage sign the Msg with S/MIME
func (m *Msg) signMessage(msg *Msg) (*Msg, error) {
currentPart := m.GetParts()[0]
currentPart.SetEncoding(EncodingUSASCII)
currentPart.SetContentType(TypeTextPlain)
content, err := currentPart.GetContent()
if err != nil {
return nil, errors.New("failed to extract content from part")
}
signedContent, err := m.sMime.Sign(content)
if err != nil {
return nil, errors.New("failed to sign message")
}
signedPart := msg.newPart(
typeSMimeSigned,
WithPartEncoding(EncodingB64),
WithContentDisposition(DispositionSMime),
)
signedPart.SetContent(*signedContent)
msg.parts = append(msg.parts, signedPart)
return msg, nil
}
// WriteTo writes the formated Msg into a give io.Writer and satisfies the io.WriteTo interface
func (m *Msg) WriteTo(writer io.Writer) (int64, error) {
mw := &msgWriter{writer: writer, charset: m.charset, encoder: m.encoder}
msg := m.applyMiddlewares(m)
if m.sMime != nil {
signedMsg, err := m.signMessage(msg)
if err != nil {
return 0, err
}
msg = signedMsg
}
mw.writeMsg(msg)
return mw.bytesWritten, mw.err
}
// WriteToSkipMiddleware writes the formated Msg into a give io.Writer and satisfies
// the io.WriteTo interface but will skip the given Middleware
func (m *Msg) WriteToSkipMiddleware(writer io.Writer, middleWareType MiddlewareType) (int64, error) {
var origMiddlewares, middlewares []Middleware
origMiddlewares = m.middlewares
for i := range m.middlewares {
if m.middlewares[i].Type() == middleWareType {
continue
}
middlewares = append(middlewares, m.middlewares[i])
}
m.middlewares = middlewares
mw := &msgWriter{writer: writer, charset: m.charset, encoder: m.encoder}
mw.writeMsg(m.applyMiddlewares(m))
m.middlewares = origMiddlewares
return mw.bytesWritten, mw.err
}
// Write is an alias method to WriteTo due to compatibility reasons
func (m *Msg) Write(writer io.Writer) (int64, error) {
return m.WriteTo(writer)
}
// appendFile adds a File to the Msg (as attachment or embed)
func (m *Msg) appendFile(files []*File, file *File, opts ...FileOption) []*File {
// Override defaults with optionally provided FileOption functions
for _, opt := range opts {
if opt == nil {
continue
}
opt(file)
}
if files == nil {
return []*File{file}
}
return append(files, file)
}
// WriteToFile stores the Msg as file on disk. It will try to create the given filename
// Already existing files will be overwritten
func (m *Msg) WriteToFile(name string) error {
file, err := os.Create(name)
if err != nil {
return fmt.Errorf("failed to create output file: %w", err)
}
defer func() { _ = file.Close() }()
_, err = m.WriteTo(file)
if err != nil {
return fmt.Errorf("failed to write to output file: %w", err)
}
return file.Close()
}
// WriteToSendmail returns WriteToSendmailWithCommand with a default sendmail path
func (m *Msg) WriteToSendmail() error {
return m.WriteToSendmailWithCommand(SendmailPath)
}
// WriteToSendmailWithCommand returns WriteToSendmailWithContext with a default timeout
// of 5 seconds and a given sendmail path
func (m *Msg) WriteToSendmailWithCommand(sendmailPath string) error {
ctx, cancel := context.WithTimeout(context.Background(), time.Second*5)
defer cancel()
return m.WriteToSendmailWithContext(ctx, sendmailPath)
}
// WriteToSendmailWithContext opens an pipe to the local sendmail binary and tries to send the
// mail though that. It takes a context.Context, the path to the sendmail binary and additional
// arguments for the sendmail binary as parameters
func (m *Msg) WriteToSendmailWithContext(ctx context.Context, sendmailPath string, args ...string) error {
cmdCtx := exec.CommandContext(ctx, sendmailPath)
cmdCtx.Args = append(cmdCtx.Args, "-oi", "-t")
cmdCtx.Args = append(cmdCtx.Args, args...)
stdErr, err := cmdCtx.StderrPipe()
if err != nil {
return fmt.Errorf("failed to set STDERR pipe: %w", err)
}
stdIn, err := cmdCtx.StdinPipe()
if err != nil {
return fmt.Errorf("failed to set STDIN pipe: %w", err)
}
if stdErr == nil || stdIn == nil {
return fmt.Errorf("received nil for STDERR or STDIN pipe")
}
// Start the execution and write to STDIN
if err = cmdCtx.Start(); err != nil {
return fmt.Errorf("could not start sendmail execution: %w", err)
}
_, err = m.WriteTo(stdIn)
if err != nil {
if !errors.Is(err, syscall.EPIPE) {
return fmt.Errorf("failed to write mail to buffer: %w", err)
}
}
// Close STDIN and wait for completion or cancellation of the sendmail executable
if err = stdIn.Close(); err != nil {
return fmt.Errorf("failed to close STDIN pipe: %w", err)
}
// Read the stderr pipe for possible errors
sendmailErr, err := io.ReadAll(stdErr)
if err != nil {
return fmt.Errorf("failed to read STDERR pipe: %w", err)
}
if len(sendmailErr) > 0 {
return fmt.Errorf("sendmail command failed: %s", string(sendmailErr))
}
if err = cmdCtx.Wait(); err != nil {
return fmt.Errorf("sendmail command execution failed: %w", err)
}
return nil
}
// NewReader returns a Reader type that satisfies the io.Reader interface.
//
// IMPORTANT: when creating a new Reader, the current state of the Msg is taken, as
// basis for the Reader. If you perform changes on Msg after creating the Reader, these
// changes will not be reflected in the Reader. You will have to use Msg.UpdateReader
// first to update the Reader's buffer with the current Msg content
func (m *Msg) NewReader() *Reader {
reader := &Reader{}
buffer := bytes.Buffer{}
_, err := m.Write(&buffer)
if err != nil {
reader.err = fmt.Errorf("failed to write Msg to Reader buffer: %w", err)
}
reader.buffer = buffer.Bytes()
return reader
}
// UpdateReader will update a Reader with the content of the given Msg and reset the
// Reader position to the start
func (m *Msg) UpdateReader(reader *Reader) {
buffer := bytes.Buffer{}
_, err := m.Write(&buffer)
reader.Reset()
reader.buffer = buffer.Bytes()
reader.err = err
}
// HasSendError returns true if the Msg experienced an error during the message delivery and the
// sendError field of the Msg is not nil
func (m *Msg) HasSendError() bool {
return m.sendError != nil
}
// SendErrorIsTemp returns true if the Msg experienced an error during the message delivery and the
// corresponding error was of temporary nature and should be retried later
func (m *Msg) SendErrorIsTemp() bool {
var err *SendError
if errors.As(m.sendError, &err) && err != nil {
return err.isTemp
}
return false
}
// SendError returns the sendError field of the Msg
func (m *Msg) SendError() error {
return m.sendError
}
// encodeString encodes a string based on the configured message encoder and the corresponding
// charset for the Msg
func (m *Msg) encodeString(str string) string {
return m.encoder.Encode(string(m.charset), str)
}
// hasAlt returns true if the Msg has more than one part
func (m *Msg) hasAlt() bool {
count := 0
for _, part := range m.parts {
if !part.isDeleted {
count++
}
}
return count > 1 && m.pgptype == 0
}
// hasMixed returns true if the Msg has mixed parts
func (m *Msg) hasMixed() bool {
return m.pgptype == 0 && ((len(m.parts) > 0 && len(m.attachments) > 0) || len(m.attachments) > 1)
}
// hasSMime returns true if the Msg has should be signed with S/MIME
func (m *Msg) hasSMime() bool {
return m.sMime != nil
}
// hasRelated returns true if the Msg has related parts
func (m *Msg) hasRelated() bool {
return m.pgptype == 0 && ((len(m.parts) > 0 && len(m.embeds) > 0) || len(m.embeds) > 1)
}
// hasPGPType returns true if the Msg should be treated as PGP encoded message
func (m *Msg) hasPGPType() bool {
return m.pgptype > 0
}
// newPart returns a new Part for the Msg
func (m *Msg) newPart(contentType ContentType, opts ...PartOption) *Part {
p := &Part{
contentType: contentType,
charset: m.charset,
encoding: m.encoding,
}
// Override defaults with optionally provided MsgOption functions
for _, opt := range opts {
if opt == nil {
continue
}
opt(p)
}
return p
}
// setEncoder creates a new mime.WordEncoder based on the encoding setting of the message
func (m *Msg) setEncoder() {
m.encoder = getEncoder(m.encoding)
}
// checkUserAgent checks if a useragent/x-mailer is set and if not will set a default
// version string
func (m *Msg) checkUserAgent() {
if m.noDefaultUserAgent {
return
}
_, uaok := m.genHeader[HeaderUserAgent]
_, xmok := m.genHeader[HeaderXMailer]
if !uaok && !xmok {
m.SetUserAgent(fmt.Sprintf("go-mail v%s // https://github.com/wneessen/go-mail",
VERSION))
}
}
// addDefaultHeader sets some default headers, if they haven't been set before
func (m *Msg) addDefaultHeader() {
if _, ok := m.genHeader[HeaderDate]; !ok {
m.SetDate()
}
if _, ok := m.genHeader[HeaderMessageID]; !ok {
m.SetMessageID()
}
m.SetGenHeader(HeaderMIMEVersion, string(m.mimever))
}
// fileFromEmbedFS returns a File pointer from a given file in the provided embed.FS
func fileFromEmbedFS(name string, fs *embed.FS) (*File, error) {
_, err := fs.Open(name)
if err != nil {
return nil, fmt.Errorf("failed to open file from embed.FS: %w", err)
}
return &File{
Name: filepath.Base(name),
Header: make(map[string][]string),
Writer: func(writer io.Writer) (int64, error) {
file, err := fs.Open(name)
if err != nil {
return 0, err
}
numBytes, err := io.Copy(writer, file)
if err != nil {
_ = file.Close()
return numBytes, fmt.Errorf("failed to copy file to io.Writer: %w", err)
}
return numBytes, file.Close()
},
}, nil
}
// fileFromFS returns a File pointer from a given file in the system's file system
func fileFromFS(name string) *File {
_, err := os.Stat(name)
if err != nil {
return nil
}
return &File{
Name: filepath.Base(name),
Header: make(map[string][]string),
Writer: func(writer io.Writer) (int64, error) {
file, err := os.Open(name)
if err != nil {
return 0, err
}
numBytes, err := io.Copy(writer, file)
if err != nil {
_ = file.Close()
return numBytes, fmt.Errorf("failed to copy file to io.Writer: %w", err)
}
return numBytes, file.Close()
},
}
}
// fileFromReader returns a File pointer from a given io.Reader
func fileFromReader(name string, reader io.Reader) (*File, error) {
d, err := io.ReadAll(reader)
if err != nil {
return &File{}, err
}
byteReader := bytes.NewReader(d)
return &File{
Name: name,
Header: make(map[string][]string),
Writer: func(writer io.Writer) (int64, error) {
readBytes, copyErr := io.Copy(writer, byteReader)
if copyErr != nil {
return readBytes, copyErr
}
_, copyErr = byteReader.Seek(0, io.SeekStart)
return readBytes, copyErr
},
}, nil
}
// fileFromReadSeeker returns a File pointer from a given io.ReadSeeker
func fileFromReadSeeker(name string, reader io.ReadSeeker) *File {
return &File{
Name: name,
Header: make(map[string][]string),
Writer: func(writer io.Writer) (int64, error) {
readBytes, err := io.Copy(writer, reader)
if err != nil {
return readBytes, err
}
_, err = reader.Seek(0, io.SeekStart)
return readBytes, err
},
}
}
// fileFromHTMLTemplate returns a File pointer form a given html/template.Template
func fileFromHTMLTemplate(name string, tpl *ht.Template, data interface{}) (*File, error) {
if tpl == nil {
return nil, errors.New(errTplPointerNil)
}
buffer := bytes.Buffer{}
if err := tpl.Execute(&buffer, data); err != nil {
return nil, fmt.Errorf(errTplExecuteFailed, err)
}
return fileFromReader(name, &buffer)
}
// fileFromTextTemplate returns a File pointer form a given text/template.Template
func fileFromTextTemplate(name string, tpl *tt.Template, data interface{}) (*File, error) {
if tpl == nil {
return nil, errors.New(errTplPointerNil)
}
buffer := bytes.Buffer{}
if err := tpl.Execute(&buffer, data); err != nil {
return nil, fmt.Errorf(errTplExecuteFailed, err)
}
return fileFromReader(name, &buffer)
}
// getEncoder creates a new mime.WordEncoder based on the encoding setting of the message
func getEncoder(enc Encoding) mime.WordEncoder {
switch enc {
case EncodingQP:
return mime.QEncoding
case EncodingB64:
return mime.BEncoding
default:
return mime.QEncoding
}
}
// writeFuncFromBuffer is a common method to convert a byte buffer into a writeFunc as
// often required by this library
func writeFuncFromBuffer(buffer *bytes.Buffer) func(io.Writer) (int64, error) {
writeFunc := func(w io.Writer) (int64, error) {
numBytes, err := w.Write(buffer.Bytes())
return int64(numBytes), err
}
return writeFunc
}