go-mail/README.md

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# go-mail - Simple and easy way to send mails in Go
[![Go Report Card](https://goreportcard.com/badge/github.com/wneessen/go-mail)](https://goreportcard.com/report/github.com/wneessen/go-mail) [![Build Status](https://api.cirrus-ci.com/github/wneessen/go-mail.svg)](https://cirrus-ci.com/github/wneessen/go-mail) <a href="https://ko-fi.com/D1D24V9IX"><img src="https://uploads-ssl.webflow.com/5c14e387dab576fe667689cf/5cbed8a4ae2b88347c06c923_BuyMeACoffee_blue.png" height="20" alt="buy ma a coffee"></a>
The main idea of this library was to provide a simple interface to sending mails for
my [JS-Mailer](https://github.com/wneessen/js-mailer) project. It quickly evolved into a full-fledged mail library.
go-mail follows idiomatic Go style and best practice. It's only dependency is the Go Standard Library. It combines a lot
of functionality from the standard library to give easy and convenient access to mail and SMTP related tasks.
Parts of this library (especially some parts of [msgwriter.go](msgwriter.go)) have been forked/ported from the
[go-mail/mail](https://github.com/go-mail/mail) respectively [go-gomail/gomail](https://github.com/go-gomail/gomail)
which both seems to not be maintained anymore.
## Features
Some of the features of this library:
* [X] Only Standard Library dependant
* [X] Modern, idiomatic Go
* [X] Sane and secure defaults
* [X] Explicit SSL/TLS support
* [X] Implicit StartTLS support with different policies
* [X] Makes use of contexts for a better control flow and timeout/cancelation handling
* [X] SMTP Auth support (LOGIN, PLAIN, CRAM-MD)
* [X] RFC5322 compliant mail address validation
* [X] Support for common mail header field generation (Message-ID, Date, Bulk-Precedence, Priority, etc.)
* [X] Reusing the same SMTP connection to send multiple mails
* [X] Support for attachments and inline embeds
* [ ] Support for different encodings (existing but not fully tested)
go-mail works like a programatic email client and provides lots of methods and functionalities you would consider
standard in a MUA.
## Examples
The package is shipped with GoDoc example code for difference scenarios. Check them out on its
[GoDoc page](https://pkg.go.dev/github.com/wneessen/go-mail#pkg-examples)
For ease of use, here is a full usage example:
```go
package main
import (
"fmt"
"github.com/wneessen/go-mail"
"os"
)
func main() {
// Create a new mail message
m := mail.NewMsg()
// To set address header fields like "From", "To", "Cc" or "Bcc" you have different methods
// at your hands. Some perform input validation, some ignore invalid addresses. Some perform
// the formating for you.
//
if err := m.FromFormat("Toni Tester", "sender@example.com"); err != nil {
fmt.Printf("failed to set FROM address: %s\n", err)
os.Exit(1)
}
if err := m.To(`"Max Mastermind <rcpt@example.com>"`); err != nil {
fmt.Printf("failed to set TO address: %s\n", err)
os.Exit(1)
}
m.CcIgnoreInvalid("cc@example.com")
// Set a subject line
m.Subject("This is a great email")
// And some other common headers
m.SetDate() // Sets a valid "Date" header field with the current time
m.SetMessageID() // Generates a valid and unique "Message-ID"
m.SetBulk() // Sets the "Precedence"-Header to "bulk" to indicate a "bulk mail"
// Add your mail message to body
m.SetBodyString(mail.TypeTextPlain, "This is a great message body text.")
// Attach a file from your local FS
// We override the attachment name using the WithFileName() Option
m.AttachFile("/home/ttester/test.txt", mail.WithFileName("attachment.txt"))
// Next let's create a Client
// We have lots of With* options at our disposal to stear the Client. It will set sane
// options by default, though
//
// Let's assume we need to perform SMTP AUTH with the sending server, though. Since we
// use SMTP PLAIN AUTH, let's also make sure to enforce strong TLS
host := "relay.example.com"
c, err := mail.NewClient(host,
mail.WithSMTPAuth(mail.SMTPAuthPlain), mail.WithUsername("ttester"),
mail.WithPassword("V3rySecUr3!Pw."), mail.WithTLSPolicy(mail.TLSMandatory))
if err != nil {
fmt.Printf("failed to create new mail client: %s\n", err)
os.Exit(1)
}
// Now that we have our client, we can connect to the server and send our mail message
// via the convenient DialAndSend() method. You have the option to Dial() and Send()
// seperately as well
if err := c.DialAndSend(m); err != nil {
fmt.Printf("failed to send mail: %s\n", err)
os.Exit(1)
}
fmt.Println("Mail successfully sent.")
}
```