package smtp import ( "crypto/tls" "fmt" "io" "net" "net/mail" "time" ) type ReplyLine struct { Code int Message string } var ( ReplyOK = ReplyLine{250, "OK"} ReplyBadSyntax = ReplyLine{501, "syntax error"} ReplyBadSequence = ReplyLine{503, "bad sequence of commands"} ReplyBadMailbox = ReplyLine{550, "mailbox unavailable"} ) type Envelope struct { RemoteAddr net.Addr EHLO string MailFrom mail.Address RcptTo []mail.Address Data []byte Received time.Time ID string } func WriteEnvelopeForDelivery(w io.Writer, e Envelope) { fmt.Fprintf(w, "Delivered-To: <%s>\r\n", e.RcptTo[0].Address) fmt.Fprintf(w, "Return-Path: <%s>\r\n", e.MailFrom.Address) w.Write(e.Data) } type Server interface { Name() string TLSConfig() *tls.Config OnEHLO() *ReplyLine VerifyAddress(mail.Address) ReplyLine OnMessageDelivered(Envelope) *ReplyLine } type EmptyServerCallbacks struct{} func (*EmptyServerCallbacks) TLSConfig() *tls.Config { return nil } func (*EmptyServerCallbacks) OnEHLO() *ReplyLine { return nil } func (*EmptyServerCallbacks) VerifyAddress(mail.Address) ReplyLine { return ReplyOK } func (*EmptyServerCallbacks) OnMessageDelivered(Envelope) *ReplyLine { return nil }