IssueTracker

We are encountering an issue with the Gmail API where some emails are sent with garbled characters.

Issue Description: The issue occurs intermittently. The same email (identical content, sender address, and recipient) will sometimes be sent with garbled characters.

We are using Go to interact with the Gmail API. The code snippet for generating the raw email is:

func (r *GmailRepo) createRawEmail(mail *Mail) (raw string) {
   header := make(textproto.MIMEHeader)
   header.Set("From", mime.BEncoding.Encode("UTF-8", mail.From))
   header.Set("To", mime.BEncoding.Encode("UTF-8", strings.Join(mail.To, ", ")))
   header.Set("Subject", mime.BEncoding.Encode("UTF-8", mail.Subject))
   if len(mail.CC) > 0 {
      ccs := make([]string, 0, len(mail.CC))
      for _, v := range mail.CC {
         v = strings.Trim(v, " ")
         ccs = append(ccs, v)
      }
      header.Set("CC", mime.BEncoding.Encode("UTF-8", strings.Join(ccs, ", ")))
   }
   if len(mail.BCC) > 0 {
      bccs := make([]string, 0, len(mail.BCC))
      for _, v := range mail.BCC {
         v = strings.Trim(v, " ")
         bccs = append(bccs, v)
      }
      header.Set("BCC", mime.BEncoding.Encode("UTF-8", strings.Join(bccs, ", ")))
   }
   contentType := "text/plain; charset=\"UTF-8\""
   if mail.IsHTML {
      contentType = "text/html; charset=\"UTF-8\""
   }
   header.Set("MIME-Version", "1.0")
   header.Set("Content-Type", contentType)
   header.Set("Content-Transfer-Encoding", "base64")
   var msg []string
   for k, v := range header {
      msg = append(msg, fmt.Sprintf("%s: %s", k, v[0]))
   }
   msg = append(msg, "")
   msg = append(msg, mail.Body)
   raw = strings.Join(msg, "\r\n")
   return base64.URLEncoding.EncodeToString([]byte(raw))
}

It would be great if you could help us with solving this problem. Thank you!