Add option to convert CRLF to LF line endings for sendmail (#18075) It appears that several versions of sendmail require that the mail is sent to them with LF line endings instead of CRLF endings - which of course they will then convert back to CRLF line endings to comply with the SMTP standard. This PR adds another setting SENDMAIL_CONVERT_CRLF which will pass the message writer through a filter. This will filter out and convert CRLFs to LFs before writing them out to sendmail. Fix #18024 Signed-off-by: Andrew Thornton <art27@cantab.net>

Changes

4 changed files (+20/-7)

• custom/conf/app.example.ini
  • @@ -1494,6 +1494,9 @@ PATH =
    ;; ;; Timeout for Sendmail ;SENDMAIL_TIMEOUT = 5m + ;; + ;; convert \r\n to \n for Sendmail + ;SENDMAIL_CONVERT_CRLF = true ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
• docs/content/doc/advanced/config-cheat-sheet.en-us.md
  • @@ -667,6 +667,7 @@ Define allowed algorithms and their minimum key length (use -1 to disable a type
    command or full path). - `SENDMAIL_ARGS`: **_empty_**: Specify any extra sendmail arguments. - `SENDMAIL_TIMEOUT`: **5m**: default timeout for sending email through sendmail + - `SENDMAIL_CONVERT_CRLF`: **true**: Most versions of sendmail prefer LF line endings rather than CRLF line endings. Set this to false if your version of sendmail requires CRLF line endings. - `SEND_BUFFER_LEN`: **100**: Buffer length of mailing queue. **DEPRECATED** use `LENGTH` in `[queue.mailer]` ## Cache (`cache`)
• modules/setting/mailer.go
  • @@ -37,9 +37,10 @@ type Mailer struct {
    IsTLSEnabled bool // Sendmail sender - SendmailPath string - SendmailArgs []string - SendmailTimeout time.Duration + SendmailPath string + SendmailArgs []string + SendmailTimeout time.Duration + SendmailConvertCRLF bool } var (
  • @@ -71,8 +72,9 @@ func newMailService() {
    IsTLSEnabled: sec.Key("IS_TLS_ENABLED").MustBool(), SubjectPrefix: sec.Key("SUBJECT_PREFIX").MustString(""), - SendmailPath: sec.Key("SENDMAIL_PATH").MustString("sendmail"), - SendmailTimeout: sec.Key("SENDMAIL_TIMEOUT").MustDuration(5 * time.Minute), + SendmailPath: sec.Key("SENDMAIL_PATH").MustString("sendmail"), + SendmailTimeout: sec.Key("SENDMAIL_TIMEOUT").MustDuration(5 * time.Minute), + SendmailConvertCRLF: sec.Key("SENDMAIL_CONVERT_CRLF").MustBool(true), } MailService.From = sec.Key("FROM").MustString(MailService.User) MailService.EnvelopeFrom = sec.Key("ENVELOPE_FROM").MustString("")
• services/mailer/mailer.go
  • @@ -290,13 +290,20 @@ func (s *sendmailSender) Send(from string, to []string, msg io.WriterTo) error {
    return err } - _, err = msg.WriteTo(pipe) + if setting.MailService.SendmailConvertCRLF { + buf := &strings.Builder{} + _, err = msg.WriteTo(buf) + if err == nil { + _, err = strings.NewReplacer("\r\n", "\n").WriteString(pipe, buf.String()) + } + } else { + _, err = msg.WriteTo(pipe) + } // we MUST close the pipe or sendmail will hang waiting for more of the message // Also we should wait on our sendmail command even if something fails closeError = pipe.Close() waitError = cmd.Wait() - if err != nil { return err } else if closeError != nil {