server: Correct protocol name in greeting banner.

conn.go

@@ -924,7 +924,11 @@ func (c *Conn) Reject() {
 }
 
 func (c *Conn) greet() {
-	c.writeResponse(220, NoEnhancedCode, fmt.Sprintf("%v ESMTP Service Ready", c.server.Domain))
+	protocol := "ESMTP"
+	if c.server.LMTP {
+		protocol = "LMTP"
+	}
+	c.writeResponse(220, NoEnhancedCode, fmt.Sprintf("%v %s Service Ready", c.server.Domain, protocol))
 }
 
 func (c *Conn) writeResponse(code int, enhCode EnhancedCode, text ...string) {

lmtp_server_test.go

@@ -4,12 +4,24 @@ import (
 	"bufio"
 	"errors"
 	"io"
+	"net"
 	"strings"
 	"testing"
 
 	"github.com/emersion/go-smtp"
 )
 
+func testServerGreetedLMTP(t *testing.T, fn ...serverConfigureFunc) (be *backend, s *smtp.Server, c net.Conn, scanner *bufio.Scanner) {
+	be, s, c, scanner = testServer(t, fn...)
+
+	scanner.Scan()
+	if scanner.Text() != "220 localhost LMTP Service Ready" {
+		t.Fatal("Invalid greeting:", scanner.Text())
+	}
+
+	return
+}
+
 func sendDeliveryCmdsLMTP(t *testing.T, scanner *bufio.Scanner, c io.Writer) {
 	sendLHLO(t, scanner, c)
 
@@ -43,7 +55,7 @@ func sendLHLO(t *testing.T, scanner *bufio.Scanner, c io.Writer) {
 }
 
 func TestServer_LMTP(t *testing.T) {
-	be, s, c, scanner := testServerGreeted(t, func(s *smtp.Server) {
+	be, s, c, scanner := testServerGreetedLMTP(t, func(s *smtp.Server) {
 		s.LMTP = true
 		be := s.Backend.(*backend)
 		be.implementLMTPData = true
@@ -80,7 +92,7 @@ func TestServer_LMTP_Early(t *testing.T) {
 
 	lmtpStatusSync := make(chan struct{})
 
-	be, s, c, scanner := testServerGreeted(t, func(s *smtp.Server) {
+	be, s, c, scanner := testServerGreetedLMTP(t, func(s *smtp.Server) {
 		s.LMTP = true
 		be := s.Backend.(*backend)
 		be.implementLMTPData = true
@@ -124,7 +136,7 @@ func TestServer_LMTP_Expand(t *testing.T) {
 	// correctly expands results if backend doesn't
 	// implement LMTPSession.
 
-	be, s, c, scanner := testServerGreeted(t, func(s *smtp.Server) {
+	be, s, c, scanner := testServerGreetedLMTP(t, func(s *smtp.Server) {
 		s.LMTP = true
 	})
 	defer s.Close()
@@ -147,7 +159,7 @@ func TestServer_LMTP_Expand(t *testing.T) {
 }
 
 func TestServer_LMTP_DuplicatedRcpt(t *testing.T) {
-	be, s, c, scanner := testServerGreeted(t, func(s *smtp.Server) {
+	be, s, c, scanner := testServerGreetedLMTP(t, func(s *smtp.Server) {
 		s.LMTP = true
 		be := s.Backend.(*backend)
 		be.implementLMTPData = true