examples/main.go

@@ -22,9 +22,10 @@ var DatabaseBackend = smtp.DatabaseBackend{
 
 // AuthenticationBackend is a smtp.AuthenticationBackend implementation that always returns a fixed address for Authenticate.
 var AuthenticationBackend = smtp.AuthenticationBackend{
-	Authenticate: func(initial string, conn *textproto.Conn) (smtp.CheckAddress, error) {
-		return func(address *smtp.Address) (bool, error) {
-			return true, nil
+	Authenticate: func(initial string, conn *textproto.Conn) (*smtp.Address, error) {
+		return &smtp.Address{
+			Name:    "test",
+			Address: "example.org",
 		}, nil
 	},
 }

smtp.go

@@ -58,8 +58,7 @@ type DatabaseBackend struct {
 
 // AuthenticationBackend is a struct that represents an authentication backend
 type AuthenticationBackend struct {
-	Authenticate        func(initial string, conn *textproto.Conn) (CheckAddress, error)
-	SupportedMechanisms []string
+	Authenticate func(initial string, conn *textproto.Conn) (CheckAddress, error)
 }
 
 type CheckAddress func(*Address) (bool, error)
@@ -212,6 +211,8 @@ func (fr *Receiver) handleConnection(conn net.Conn) {
 		return
 	}
 
+	fmt.Println("Connection from", conn.RemoteAddr().String())
+
 	for {
 		line, err := textProto.ReadLine()
 		if err != nil {
@@ -282,9 +283,6 @@ func (fr *Receiver) handleConnection(conn net.Conn) {
 				if fr.enforceTLS {
 					capabilities = append(capabilities, "250-REQUIRETLS")
 				}
-				if fr.auth.SupportedMechanisms != nil {
-					capabilities = append(capabilities, "250-AUTH "+strings.Join(fr.auth.SupportedMechanisms, " "))
-				}
 				capabilities = append(capabilities, defaultCapabilities...)
 				state.HELO = true
 				err = speakMultiLine(textProto, capabilities)
@@ -326,7 +324,7 @@ func (fr *Receiver) handleConnection(conn net.Conn) {
 			} else {
 				checkAddress, err := fr.auth.Authenticate(strings.TrimPrefix(line, "AUTH "), textProto)
 				if err != nil {
-					_ = textProto.PrintfLine(err.Error())
+					_ = textProto.PrintfLine("421 4.7.0 Temporary server error")
 					_ = conn.Close()
 					return
 				}
@@ -590,6 +588,7 @@ func (fr *Receiver) handleConnection(conn net.Conn) {
 					Host: strings.Split(conn.RemoteAddr().String(), ":")[0],
 				}
 				go sendEmail(SenderArgs{
+					Hostname:   fr.hostname,
 					EnforceTLS: fr.enforceTLS,
 				}, mail, fr.database, queueID)
 
@@ -618,6 +617,7 @@ func (fr *Receiver) handleConnection(conn net.Conn) {
 
 // SenderArgs is a struct that represents the arguments for the Sender
 type SenderArgs struct {
+	Hostname   string
 	EnforceTLS bool
 }
 
@@ -648,7 +648,7 @@ func Send(args SenderArgs, mail *Mail, conn net.Conn, mxHost string) (err error)
 		return errors.New("unexpected greeting - " + line)
 	}
 
-	err = textConn.PrintfLine("EHLO %s", mxHost)
+	err = textConn.PrintfLine("EHLO %s", args.Hostname)
 	if err != nil {
 		return err
 	}
@@ -682,11 +682,16 @@ func Send(args SenderArgs, mail *Mail, conn net.Conn, mxHost string) (err error)
 			InsecureSkipVerify: false,
 		})
 
+		err = tlsConn.Handshake()
+		if err != nil {
+			return err
+		}
+
 		textConn = textproto.NewConn(tlsConn)
 
 		// Just use HELO, no point using EHLO when we already have all the capabilities
 		// This also gets us out of using readMultilineCodeResponse
-		err = textConn.PrintfLine("HELO %s", mxHost)
+		err = textConn.PrintfLine("HELO %s", args.Hostname)
 		if err != nil {
 			return err
 		}
@@ -709,7 +714,10 @@ func Send(args SenderArgs, mail *Mail, conn net.Conn, mxHost string) (err error)
 	}
 
 	code, line, err = textConn.ReadCodeLine(0)
+	fmt.Println(code, line, err)
 	if err != nil {
+		// For some reason the EHLO stuff ends up here
+		fmt.Println("5")
 		return err
 	}
 
@@ -724,7 +732,9 @@ func Send(args SenderArgs, mail *Mail, conn net.Conn, mxHost string) (err error)
 		}
 
 		code, line, err = textConn.ReadCodeLine(0)
+		fmt.Println(code, line, err)
 		if err != nil {
+			fmt.Println("6")
 			return err
 		}
 
@@ -739,7 +749,9 @@ func Send(args SenderArgs, mail *Mail, conn net.Conn, mxHost string) (err error)
 	}
 
 	code, line, err = textConn.ReadCodeLine(0)
+	fmt.Println(code, line, err)
 	if err != nil {
+		fmt.Println("7")
 		return err
 	}
 
@@ -759,7 +771,9 @@ func Send(args SenderArgs, mail *Mail, conn net.Conn, mxHost string) (err error)
 	}
 
 	code, line, err = textConn.ReadCodeLine(0)
+	fmt.Println(code, line, err)
 	if err != nil {
+		fmt.Println("8")
 		return err
 	}
 
@@ -773,7 +787,9 @@ func Send(args SenderArgs, mail *Mail, conn net.Conn, mxHost string) (err error)
 	}
 
 	code, line, err = textConn.ReadCodeLine(0)
+	fmt.Println(code, line, err)
 	if err != nil {
+		fmt.Println("9")
 		return err
 	}