.cirrus.yml

@@ -6,9 +6,9 @@ freebsd_task:
   name: FreeBSD
 
   matrix:
-    - name: FreeBSD 13.3
+    - name: FreeBSD 13.2
       freebsd_instance:
-        image_family: freebsd-13-3
+        image_family: freebsd-13-2
     - name: FreeBSD 14.0
       freebsd_instance:
         image_family: freebsd-14-0

.github/workflows/codecov.yml

@@ -36,7 +36,7 @@ jobs:
     strategy:
       matrix:
         os: [ubuntu-latest, macos-latest, windows-latest]
-        go: ['1.20', '1.21', '1.22', '1.23']
+        go: [1.18, 1.19, '1.20', '1.21', '1.22']
     steps:
     - name: Harden Runner
       uses: step-security/harden-runner@5c7944e73c4c2a096b17a9cb74d65b6c2bbafbde # v2.9.1
@@ -50,14 +50,14 @@ jobs:
       with:
         go-version: ${{ matrix.go }}
     - name: Install sendmail
-      if: matrix.go == '1.23' && matrix.os == 'ubuntu-latest'
+      if: matrix.go == '1.22' && matrix.os == 'ubuntu-latest'
       run: |
         sudo apt-get -y install sendmail; which sendmail
     - name: Run Tests
       run: |
         go test -v -race --coverprofile=coverage.coverprofile --covermode=atomic ./...
     - name: Upload coverage to Codecov
-      if: success() && matrix.go == '1.23' && matrix.os == 'ubuntu-latest'
+      if: success() && matrix.go == '1.22' && matrix.os == 'ubuntu-latest'
       uses: codecov/codecov-action@e28ff129e5465c2c0dcc6f003fc735cb6ae0c673 # v4.5.0
       with:
         token: ${{ secrets.CODECOV_TOKEN }} # not required for public repos

.github/workflows/golangci-lint.yml

@@ -26,7 +26,7 @@ jobs:
 
       - uses: actions/setup-go@0a12ed9d6a96ab950c8f026ed9f722fe0da7ef32 # v5.0.2
         with:
-          go-version: '1.23'
+          go-version: '1.22'
       - uses: actions/checkout@f43a0e5ff2bd294095638e18286ca9a3d1956744 # v3.6.0
       - name: golangci-lint
         uses: golangci/golangci-lint-action@aaa42aa0628b4ae2578232a66b541047968fac86 # v6.1.0

.github/workflows/sonarqube.yml

@@ -38,7 +38,7 @@ jobs:
       - name: Setup Go
         uses: actions/setup-go@0a12ed9d6a96ab950c8f026ed9f722fe0da7ef32 # v5.0.2
         with:
-          go-version: '1.23.x'
+          go-version: '1.22.x'
           
       - name: Run unit Tests
         run: |

.golangci.toml

@@ -3,9 +3,8 @@
 ## SPDX-License-Identifier: MIT
 
 [run]
-go = "1.23"
+go = "1.22"
 tests = true
-exclude-dirs = ["examples"]
 
 [linters]
 enable = ["stylecheck", "whitespace", "containedctx", "contextcheck", "decorder",

b64linebreaker.go

@@ -5,7 +5,7 @@
 package mail
 
 import (
-	"errors"
+	"fmt"
 	"io"
 )
 
@@ -26,7 +26,7 @@ var newlineBytes = []byte(SingleNewLine)
 // line length is reached
 func (l *Base64LineBreaker) Write(data []byte) (numBytes int, err error) {
 	if l.out == nil {
-		err = errors.New(ErrNoOutWriter)
+		err = fmt.Errorf(ErrNoOutWriter)
 		return
 	}
 	if l.used+len(data) < MaxBodyLength {

doc.go

@@ -6,4 +6,4 @@
 package mail
 
 // VERSION is used in the default user agent string
-const VERSION = "0.4.3"
+const VERSION = "0.4.2"

msg.go

@@ -743,7 +743,7 @@ func (m *Msg) SetBodyWriter(
 // 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)
+		return fmt.Errorf(errTplPointerNil)
 	}
 	buffer := bytes.Buffer{}
 	if err := tpl.Execute(&buffer, data); err != nil {
@@ -758,7 +758,7 @@ func (m *Msg) SetBodyHTMLTemplate(tpl *ht.Template, data interface{}, opts ...Pa
 // 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)
+		return fmt.Errorf(errTplPointerNil)
 	}
 	buf := bytes.Buffer{}
 	if err := tpl.Execute(&buf, data); err != nil {
@@ -790,7 +790,7 @@ func (m *Msg) AddAlternativeWriter(
 // 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)
+		return fmt.Errorf(errTplPointerNil)
 	}
 	buffer := bytes.Buffer{}
 	if err := tpl.Execute(&buffer, data); err != nil {
@@ -805,7 +805,7 @@ func (m *Msg) AddAlternativeHTMLTemplate(tpl *ht.Template, data interface{}, opt
 // 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)
+		return fmt.Errorf(errTplPointerNil)
 	}
 	buffer := bytes.Buffer{}
 	if err := tpl.Execute(&buffer, data); err != nil {
@@ -1314,7 +1314,7 @@ func fileFromReadSeeker(name string, reader io.ReadSeeker) *File {
 // 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)
+		return nil, fmt.Errorf(errTplPointerNil)
 	}
 	buffer := bytes.Buffer{}
 	if err := tpl.Execute(&buffer, data); err != nil {
@@ -1326,7 +1326,7 @@ func fileFromHTMLTemplate(name string, tpl *ht.Template, data interface{}) (*Fil
 // 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)
+		return nil, fmt.Errorf(errTplPointerNil)
 	}
 	buffer := bytes.Buffer{}
 	if err := tpl.Execute(&buffer, data); err != nil {

msgwriter_test.go

@@ -122,7 +122,7 @@ func TestMsgWriter_writeMsg(t *testing.T) {
 			em += fmt.Sprintf("* incorrect %q field", ea[e])
 		}
 		em += fmt.Sprintf("\n\nFull message:\n%s", ms)
-		t.Error(em)
+		t.Errorf(em)
 	}
 }
 

smtp/auth_login.go

@@ -20,15 +20,13 @@ const (
 	// extension.
 	//
 	// See: https://learn.microsoft.com/en-us/openspecs/exchange_server_protocols/ms-xlogin/.
-	LoginXUsernameChallenge      = "Username:"
-	LoginXUsernameLowerChallenge = "username:"
+	LoginXUsernameChallenge = "Username:"
 
 	// LoginXPasswordChallenge represents the Password Challenge response sent by the SMTP server per the AUTH LOGIN
 	// extension.
 	//
 	//	See: https://learn.microsoft.com/en-us/openspecs/exchange_server_protocols/ms-xlogin/.
-	LoginXPasswordChallenge      = "Password:"
-	LoginXPasswordLowerChallenge = "password:"
+	LoginXPasswordChallenge = "Password:"
 
 	// LoginXDraftUsernameChallenge represents the Username Challenge response sent by the SMTP server per the IETF
 	// draft AUTH LOGIN extension. It should be noted this extension is an expired draft which was never formally
@@ -78,9 +76,9 @@ func (a *loginAuth) Start(server *ServerInfo) (string, []byte, error) {
 func (a *loginAuth) Next(fromServer []byte, more bool) ([]byte, error) {
 	if more {
 		switch string(fromServer) {
-		case LoginXUsernameChallenge, LoginXUsernameLowerChallenge, LoginXDraftUsernameChallenge:
+		case LoginXUsernameChallenge, LoginXDraftUsernameChallenge:
 			return []byte(a.username), nil
-		case LoginXPasswordChallenge, LoginXPasswordLowerChallenge, LoginXDraftPasswordChallenge:
+		case LoginXPasswordChallenge, LoginXDraftPasswordChallenge:
 			return []byte(a.password), nil
 		default:
 			return nil, fmt.Errorf("unexpected server response: %s", string(fromServer))