.github/workflows/go.yml

@@ -1,17 +1,15 @@
-name: smtpd
+name: Go
 
 on:
   push:
     branches: [ master ]
   pull_request:
     branches: [ master ]
-  schedule:
-    - cron: '12 0 * * *'
 
 jobs:
 
   build:
-    name: Build and Test
+    name: Build
     runs-on: ubuntu-latest
     steps:
 
@@ -21,11 +19,16 @@ jobs:
         go-version: ^1.13
       id: go
 
-    - name: Check out the code
+    - name: Check out code into the Go module directory
       uses: actions/checkout@v2
 
     - name: Get dependencies
-      run: go get -v -t -d ./...
+      run: |
+        go get -v -t -d ./...
+        if [ -f Gopkg.toml ]; then
+            curl https://raw.githubusercontent.com/golang/dep/master/install.sh | sh
+            dep ensure
+        fi
 
     - name: Build
       run: go build -v .

Makefile

@@ -1,8 +0,0 @@
-test:
-	go test .
-
-dkim-proxy:
-	cd _examples && go get . && go build .
-
-testsum:
-	gotestsum --format testname

_examples/dkim-proxy/README.md

@@ -1,5 +0,0 @@
-# smtpd dkim-proxy
-
-## Important Note
-
-The dependency `github.com/eaigner/dkim` is no longer available thus the example can not be built.

_examples/dkim-proxy/go.mod

@@ -1,5 +0,0 @@
-module github.com/chrj/smtpd/_examples/dkim-proxy
-
-go 1.14
-
-require github.com/eaigner/dkim v0.0.0-20150301120808-6fe4a7ee9cfb

envelope.go

@@ -20,7 +20,7 @@ func (env *Envelope) AddReceivedLine(peer Peer) {
 	tlsDetails := ""
 
 	tlsVersions := map[uint16]string{
-    0x300:            "SSL3.0",
+		tls.VersionSSL30: "SSL3.0",
 		tls.VersionTLS10: "TLS1.0",
 		tls.VersionTLS11: "TLS1.1",
 		tls.VersionTLS12: "TLS1.2",

error.go

@@ -1,22 +0,0 @@
-package smtpd
-
-import (
-  "errors"
-  "fmt"
-)
-// Error represents an Error reported in the SMTP session.
-type Error struct {
-	Code    int    // The integer error code
-	Message string // The error message
-}
-
-// Error returns a string representation of the SMTP error
-func (e Error) Error() string { 
-  return fmt.Sprintf("%d %s", e.Code, e.Message) 
-}
-
-// ErrServerClosed is returned by the Server's Serve and ListenAndServe,
-// methods after a call to Shutdown.
-var ErrServerClosed = errors.New("smtp: Server closed")
-
-

example_test.go

@@ -5,7 +5,7 @@ import (
 	"net/smtp"
 	"strings"
 
-	"git.jmbit.de/jmb/smtpd"
+	"github.com/chrj/smtpd"
 )
 
 func ExampleServer() {

examples/dkim-proxy/main.go

@@ -4,6 +4,7 @@ package main
 import (
 	"bytes"
 	"flag"
+	"io/ioutil"
 	"log"
 	"net/smtp"
 
@@ -59,7 +60,7 @@ func main() {
 		log.Fatalf("DKIM configuration error: %v", err)
 	}
 
-	privKey, err = io.ReadFile(*privKeyFile)
+	privKey, err = ioutil.ReadFile(*privKeyFile)
 	if err != nil {
 		log.Fatalf("Couldn't read private key: %v", err)
 	}

go.mod

@@ -1,3 +1,5 @@
-module git.jmbit.de/jmb/smtpd
+module github.com/chrj/smtpd
 
-go 1.24
+go 1.14
+
+require github.com/eaigner/dkim v0.0.0-20150301120808-6fe4a7ee9cfb

onceCloseListerner.go

@@ -1,28 +0,0 @@
-package smtpd
-
-import (
-	"net"
-	"sync"
-	"sync/atomic"
-)
-
-// onceCloseListener wraps a net.Listener, protecting it from
-// multiple Close calls.
-type onceCloseListener struct {
-	net.Listener
-	once     sync.Once
-	closeErr error
-}
-
-func (oc *onceCloseListener) Close() error {
-	oc.once.Do(oc.close)
-	return oc.closeErr
-}
-
-func (oc *onceCloseListener) close() { oc.closeErr = oc.Listener.Close() }
-
-type atomicBool int32
-
-func (b *atomicBool) isSet() bool { return atomic.LoadInt32((*int32)(b)) != 0 }
-func (b *atomicBool) setTrue()    { atomic.StoreInt32((*int32)(b), 1) }
-func (b *atomicBool) setFalse()   { atomic.StoreInt32((*int32)(b), 0) }

protocol.go

@@ -7,6 +7,7 @@ import (
 	"encoding/base64"
 	"fmt"
 	"io"
+	"io/ioutil"
 	"net"
 	"net/textproto"
 	"strconv"
@@ -287,7 +288,6 @@ func (session *session) handleRCPT(cmd command) {
 }
 
 func (session *session) handleSTARTTLS(cmd command) {
-  _ = cmd
 
 	if session.tls {
 		session.reply(502, "Already running in TLS")
@@ -334,7 +334,6 @@ func (session *session) handleSTARTTLS(cmd command) {
 }
 
 func (session *session) handleDATA(cmd command) {
-  _ = cmd
 
 	if session.envelope == nil || len(session.envelope.Recipients) == 0 {
 		session.reply(502, "Missing RCPT TO command.")
@@ -372,7 +371,7 @@ func (session *session) handleDATA(cmd command) {
 	}
 
 	// Discard the rest and report an error.
-	_, err = io.Copy(io.Discard, reader)
+	_, err = io.Copy(ioutil.Discard, reader)
 
 	if err != nil {
 		// Network error, ignore
@@ -391,20 +390,17 @@ func (session *session) handleDATA(cmd command) {
 }
 
 func (session *session) handleRSET(cmd command) {
-  _ = cmd
 	session.reset()
 	session.reply(250, "Go ahead")
 	return
 }
 
 func (session *session) handleNOOP(cmd command) {
-  _ = cmd
 	session.reply(250, "Go ahead")
 	return
 }
 
 func (session *session) handleQUIT(cmd command) {
-  _ = cmd
 	session.reply(221, "OK, bye")
 	session.close()
 	return

session.go

@@ -1,162 +0,0 @@
-package smtpd
-
-import (
-  "net"
-  "bufio"
-  "strings"
-  "fmt"
-  "time"
-)
-
-type session struct {
-	server *Server
-
-	peer     Peer
-	envelope *Envelope
-
-	conn net.Conn
-
-	reader  *bufio.Reader
-	writer  *bufio.Writer
-	scanner *bufio.Scanner
-
-	tls bool
-}
-
-
-func (session *session) serve() {
-
-	defer session.close()
-
-	if !session.server.EnableProxyProtocol {
-		session.welcome()
-	}
-
-	for {
-
-		for session.scanner.Scan() {
-			line := session.scanner.Text()
-			session.logf("received: %s", strings.TrimSpace(line))
-			session.handle(line)
-		}
-
-		err := session.scanner.Err()
-
-		if err == bufio.ErrTooLong {
-
-			session.reply(500, "Line too long")
-
-			// Advance reader to the next newline
-
-			session.reader.ReadString('\n')
-			session.scanner = bufio.NewScanner(session.reader)
-
-			// Reset and have the client start over.
-
-			session.reset()
-
-			continue
-		}
-
-		break
-	}
-
-}
-
-func (session *session) reject() {
-	session.reply(421, "Too busy. Try again later.")
-	session.close()
-}
-
-func (session *session) reset() {
-	session.envelope = nil
-}
-
-func (session *session) welcome() {
-
-	if session.server.ConnectionChecker != nil {
-		err := session.server.ConnectionChecker(session.peer)
-		if err != nil {
-			session.error(err)
-			session.close()
-			return
-		}
-	}
-
-	session.reply(220, session.server.WelcomeMessage)
-
-}
-
-func (session *session) reply(code int, message string) {
-	session.logf("sending: %d %s", code, message)
-	fmt.Fprintf(session.writer, "%d %s\r\n", code, message)
-	session.flush()
-}
-
-func (session *session) flush() {
-	session.conn.SetWriteDeadline(time.Now().Add(session.server.WriteTimeout))
-	session.writer.Flush()
-	session.conn.SetReadDeadline(time.Now().Add(session.server.ReadTimeout))
-}
-
-func (session *session) error(err error) {
-	if smtpdError, ok := err.(Error); ok {
-		session.reply(smtpdError.Code, smtpdError.Message)
-	} else {
-		session.reply(502, fmt.Sprintf("%s", err))
-	}
-}
-
-func (session *session) logf(format string, v ...interface{}) {
-	if session.server.ProtocolLogger == nil {
-		return
-	}
-	session.server.ProtocolLogger.Info(fmt.Sprintf(
-		"%s [peer:%s]",
-		fmt.Sprintf(format, v...),
-		session.peer.Addr,
-	))
-
-}
-
-func (session *session) logError(err error, desc string) {
-	session.server.ProtocolLogger.Error(desc, "error", err)
-}
-
-func (session *session) extensions() []string {
-
-	extensions := []string{
-		fmt.Sprintf("SIZE %d", session.server.MaxMessageSize),
-		"8BITMIME",
-		"PIPELINING",
-	}
-
-	if session.server.EnableXCLIENT {
-		extensions = append(extensions, "XCLIENT")
-	}
-
-	if session.server.TLSConfig != nil && !session.tls {
-		extensions = append(extensions, "STARTTLS")
-	}
-
-	if session.server.Authenticator != nil && session.tls {
-		extensions = append(extensions, "AUTH PLAIN LOGIN")
-	}
-
-	return extensions
-
-}
-
-func (session *session) deliver() error {
-	if session.server.Handler != nil {
-		return session.server.Handler(session.peer, *session.envelope)
-	}
-	return nil
-}
-
-func (session *session) close() {
-	session.writer.Flush()
-	time.Sleep(200 * time.Millisecond)
-	session.conn.Close()
-}
-

smtpd.go

@@ -4,12 +4,10 @@ package smtpd
 import (
 	"bufio"
 	"crypto/tls"
-	"errors"
 	"fmt"
-	"log/slog"
 	"log"
 	"net"
-	"sync"
+	"strings"
 	"time"
 )
 
@@ -50,15 +48,7 @@ type Server struct {
 	TLSConfig *tls.Config // Enable STARTTLS support.
 	ForceTLS  bool        // Force STARTTLS usage.
 
-	ProtocolLogger *slog.Logger
-
-	// mu guards doneChan and makes closing it and listener atomic from
-	// perspective of Serve()
-	mu sync.Mutex
-	doneChan chan struct{}
-	listener *net.Listener
-	waitgrp sync.WaitGroup
-	inShutdown atomicBool // true when server is in shutdown
+	ProtocolLogger *log.Logger
 }
 
 // Protocol represents the protocol used in the SMTP session
@@ -83,6 +73,30 @@ type Peer struct {
 	TLS        *tls.ConnectionState // TLS Connection details, if on TLS
 }
 
+// Error represents an Error reported in the SMTP session.
+type Error struct {
+	Code    int    // The integer error code
+	Message string // The error message
+}
+
+// Error returns a string representation of the SMTP error
+func (e Error) Error() string { return fmt.Sprintf("%d %s", e.Code, e.Message) }
+
+type session struct {
+	server *Server
+
+	peer     Peer
+	envelope *Envelope
+
+	conn net.Conn
+
+	reader  *bufio.Reader
+	writer  *bufio.Writer
+	scanner *bufio.Scanner
+
+	tls bool
+}
+
 func (srv *Server) newSession(c net.Conn) (s *session) {
 
 	s = &session{
@@ -120,9 +134,6 @@ func (srv *Server) newSession(c net.Conn) (s *session) {
 
 // ListenAndServe starts the SMTP server and listens on the address provided
 func (srv *Server) ListenAndServe(addr string) error {
-	if srv.shuttingDown() {
-		return ErrServerClosed
-	}
 
 	srv.configureDefaults()
 
@@ -136,32 +147,24 @@ func (srv *Server) ListenAndServe(addr string) error {
 
 // Serve starts the SMTP server and listens on the Listener provided
 func (srv *Server) Serve(l net.Listener) error {
-	if srv.shuttingDown() {
-		return ErrServerClosed
-	}
 
 	srv.configureDefaults()
 
-	l = &onceCloseListener{Listener: l}
 	defer l.Close()
-	srv.listener = &l
 
 	var limiter chan struct{}
 
 	if srv.MaxConnections > 0 {
 		limiter = make(chan struct{}, srv.MaxConnections)
+	} else {
+		limiter = nil
 	}
 
 	for {
+
 		conn, e := l.Accept()
 		if e != nil {
-			select {
-			case <-srv.getDoneChan():
-				return ErrServerClosed
-			default:
-			}
-
-			if ne, ok := e.(net.Error); ok && ne.Timeout() {
+			if ne, ok := e.(net.Error); ok && ne.Temporary() {
 				time.Sleep(time.Second)
 				continue
 			}
@@ -170,10 +173,8 @@ func (srv *Server) Serve(l net.Listener) error {
 
 		session := srv.newSession(conn)
 
-		srv.waitgrp.Add(1)
-		go func() {
-			defer srv.waitgrp.Done()
 		if limiter != nil {
+			go func() {
 				select {
 				case limiter <- struct{}{}:
 					session.serve()
@@ -181,51 +182,13 @@ func (srv *Server) Serve(l net.Listener) error {
 				default:
 					session.reject()
 				}
-			} else {
-				session.serve()
-			}
 			}()
+		} else {
+			go session.serve()
 		}
 
-}
-
-// Shutdown instructs the server to shutdown, starting by closing the
-// associated listener. If wait is true, it will wait for the shutdown
-// to complete. If wait is false, Wait must be called afterwards.
-func (srv *Server) Shutdown(wait bool) error {
-	var lnerr error
-	srv.inShutdown.setTrue()
-
-	// First close the listener
-	srv.mu.Lock()
-	if srv.listener != nil {
-		lnerr = (*srv.listener).Close();
-	}
-	srv.closeDoneChanLocked()
-	srv.mu.Unlock()
-
-	// Now wait for all client connections to close
-	if wait {
-		srv.Wait()
 	}
 
-	return lnerr
-}
-
-// Wait waits for all client connections to close and the server to finish
-// shutting down.
-func (srv *Server) Wait() error {
-	if !srv.shuttingDown() {
-		return errors.New("Server has not been Shutdown")
-	}
-
-	srv.waitgrp.Wait()
-	return nil
-}
-
-// Address returns the listening address of the server
-func (srv *Server) Address() net.Addr {
-	return (*srv.listener).Addr();
 }
 
 func (srv *Server) configureDefaults() {
@@ -268,34 +231,138 @@ func (srv *Server) configureDefaults() {
 
 }
 
-// From net/http/server.go
+func (session *session) serve() {
 
-func (s *Server) shuttingDown() bool {
-	return s.inShutdown.isSet()
-}
+	defer session.close()
 
-func (s *Server) getDoneChan() <-chan struct{} {
-	s.mu.Lock()
-	defer s.mu.Unlock()
-	return s.getDoneChanLocked()
-}
-
-func (s *Server) getDoneChanLocked() chan struct{} {
-	if s.doneChan == nil {
-		s.doneChan = make(chan struct{})
+	if !session.server.EnableProxyProtocol {
+		session.welcome()
 	}
-	return s.doneChan
+
+	for {
+
+		for session.scanner.Scan() {
+			line := session.scanner.Text()
+			session.logf("received: %s", strings.TrimSpace(line))
+			session.handle(line)
+		}
+
+		err := session.scanner.Err()
+
+		if err == bufio.ErrTooLong {
+
+			session.reply(500, "Line too long")
+
+			// Advance reader to the next newline
+
+			session.reader.ReadString('\n')
+			session.scanner = bufio.NewScanner(session.reader)
+
+			// Reset and have the client start over.
+
+			session.reset()
+
+			continue
+		}
+
+		break
+	}
+
 }
 
-func (s *Server) closeDoneChanLocked() {
-	ch := s.getDoneChanLocked()
-	select {
-	case <-ch:
-		// Already closed. Don't close again.
-	default:
-		// Safe to close here. We're the only closer, guarded
-		// by s.mu.
-		close(ch)
+func (session *session) reject() {
+	session.reply(421, "Too busy. Try again later.")
+	session.close()
+}
+
+func (session *session) reset() {
+	session.envelope = nil
+}
+
+func (session *session) welcome() {
+
+	if session.server.ConnectionChecker != nil {
+		err := session.server.ConnectionChecker(session.peer)
+		if err != nil {
+			session.error(err)
+			session.close()
+			return
+		}
+	}
+
+	session.reply(220, session.server.WelcomeMessage)
+
+}
+
+func (session *session) reply(code int, message string) {
+	session.logf("sending: %d %s", code, message)
+	fmt.Fprintf(session.writer, "%d %s\r\n", code, message)
+	session.flush()
+}
+
+func (session *session) flush() {
+	session.conn.SetWriteDeadline(time.Now().Add(session.server.WriteTimeout))
+	session.writer.Flush()
+	session.conn.SetReadDeadline(time.Now().Add(session.server.ReadTimeout))
+}
+
+func (session *session) error(err error) {
+	if smtpdError, ok := err.(Error); ok {
+		session.reply(smtpdError.Code, smtpdError.Message)
+	} else {
+		session.reply(502, fmt.Sprintf("%s", err))
 	}
 }
 
+func (session *session) logf(format string, v ...interface{}) {
+	if session.server.ProtocolLogger == nil {
+		return
+	}
+	session.server.ProtocolLogger.Output(2, fmt.Sprintf(
+		"%s [peer:%s]",
+		fmt.Sprintf(format, v...),
+		session.peer.Addr,
+	))
+
+}
+
+func (session *session) logError(err error, desc string) {
+	session.logf("%s: %v ", desc, err)
+}
+
+func (session *session) extensions() []string {
+
+	extensions := []string{
+		fmt.Sprintf("SIZE %d", session.server.MaxMessageSize),
+		"8BITMIME",
+		"PIPELINING",
+	}
+
+	if session.server.EnableXCLIENT {
+		extensions = append(extensions, "XCLIENT")
+	}
+
+	if session.server.TLSConfig != nil && !session.tls {
+		extensions = append(extensions, "STARTTLS")
+	}
+
+	if session.server.Authenticator != nil && session.tls {
+		extensions = append(extensions, "AUTH PLAIN LOGIN")
+	}
+
+	return extensions
+
+}
+
+func (session *session) deliver() error {
+	if session.server.Handler != nil {
+		return session.server.Handler(session.peer, *session.envelope)
+	}
+	return nil
+}
+
+func (session *session) close() {
+	session.writer.Flush()
+	time.Sleep(200 * time.Millisecond)
+	session.conn.Close()
+}

smtpd_test.go

@@ -5,7 +5,7 @@ import (
 	"crypto/tls"
 	"errors"
 	"fmt"
-  "log/slog"
+	"log"
 	"net"
 	"net/smtp"
 	"net/textproto"
@@ -14,7 +14,7 @@ import (
 	"testing"
 	"time"
 
-	"git.jmbit.de/jmb/smtpd"
+	"github.com/chrj/smtpd"
 )
 
 var localhostCert = []byte(`-----BEGIN CERTIFICATE-----
@@ -158,7 +158,7 @@ func runsslserver(t *testing.T, server *smtpd.Server) (addr string, closer func(
 func TestSMTP(t *testing.T) {
 
 	addr, closer := runserver(t, &smtpd.Server{
-		ProtocolLogger: slog.New(slog.NewTextHandler(os.Stdout, nil)),
+		ProtocolLogger: log.New(os.Stdout, "log: ", log.Lshortfile),
 	})
 	defer closer()
 
@@ -233,7 +233,7 @@ func TestListenAndServe(t *testing.T) {
 	closer()
 
 	server := &smtpd.Server{
-		ProtocolLogger: slog.New(slog.NewTextHandler(os.Stdout, nil)),
+		ProtocolLogger: log.New(os.Stdout, "log: ", log.Lshortfile),
 	}
 
 	go func() {
@@ -258,7 +258,7 @@ func TestSTARTTLS(t *testing.T) {
 	addr, closer := runsslserver(t, &smtpd.Server{
 		Authenticator:  func(peer smtpd.Peer, username, password string) error { return nil },
 		ForceTLS:       true,
-		ProtocolLogger: slog.New(slog.NewTextHandler(os.Stdout, nil)),
+		ProtocolLogger: log.New(os.Stdout, "log: ", log.Lshortfile),
 	})
 
 	defer closer()
@@ -347,7 +347,7 @@ func TestAuthRejection(t *testing.T) {
 			return smtpd.Error{Code: 550, Message: "Denied"}
 		},
 		ForceTLS:       true,
-		ProtocolLogger: slog.New(slog.NewTextHandler(os.Stdout, nil)),
+		ProtocolLogger: log.New(os.Stdout, "log: ", log.Lshortfile),
 	})
 
 	defer closer()
@@ -371,7 +371,7 @@ func TestAuthNotSupported(t *testing.T) {
 
 	addr, closer := runsslserver(t, &smtpd.Server{
 		ForceTLS:       true,
-		ProtocolLogger: slog.New(slog.NewTextHandler(os.Stdout, nil)),
+		ProtocolLogger: log.New(os.Stdout, "log: ", log.Lshortfile),
 	})
 
 	defer closer()
@@ -398,7 +398,7 @@ func TestAuthBypass(t *testing.T) {
 			return smtpd.Error{Code: 550, Message: "Denied"}
 		},
 		ForceTLS:	true,
-		ProtocolLogger:	slog.New(slog.NewTextHandler(os.Stdout, nil)),
+		ProtocolLogger:	log.New(os.Stdout, "log: ", log.Lshortfile),
 	})
 
 	defer closer()
@@ -424,7 +424,7 @@ func TestConnectionCheck(t *testing.T) {
 		ConnectionChecker: func(peer smtpd.Peer) error {
 			return smtpd.Error{Code: 552, Message: "Denied"}
 		},
-		ProtocolLogger: slog.New(slog.NewTextHandler(os.Stdout, nil)),
+		ProtocolLogger: log.New(os.Stdout, "log: ", log.Lshortfile),
 	})
 
 	defer closer()
@@ -441,7 +441,7 @@ func TestConnectionCheckSimpleError(t *testing.T) {
 		ConnectionChecker: func(peer smtpd.Peer) error {
 			return errors.New("Denied")
 		},
-		ProtocolLogger: slog.New(slog.NewTextHandler(os.Stdout, nil)),
+		ProtocolLogger: log.New(os.Stdout, "log: ", log.Lshortfile),
 	})
 
 	defer closer()
@@ -461,7 +461,7 @@ func TestHELOCheck(t *testing.T) {
 			}
 			return smtpd.Error{Code: 552, Message: "Denied"}
 		},
-		ProtocolLogger: slog.New(slog.NewTextHandler(os.Stdout, nil)),
+		ProtocolLogger: log.New(os.Stdout, "log: ", log.Lshortfile),
 	})
 
 	defer closer()
@@ -483,7 +483,7 @@ func TestSenderCheck(t *testing.T) {
 		SenderChecker: func(peer smtpd.Peer, addr string) error {
 			return smtpd.Error{Code: 552, Message: "Denied"}
 		},
-		ProtocolLogger: slog.New(slog.NewTextHandler(os.Stdout, nil)),
+		ProtocolLogger: log.New(os.Stdout, "log: ", log.Lshortfile),
 	})
 
 	defer closer()
@@ -505,7 +505,7 @@ func TestRecipientCheck(t *testing.T) {
 		RecipientChecker: func(peer smtpd.Peer, addr string) error {
 			return smtpd.Error{Code: 552, Message: "Denied"}
 		},
-		ProtocolLogger: slog.New(slog.NewTextHandler(os.Stdout, nil)),
+		ProtocolLogger: log.New(os.Stdout, "log: ", log.Lshortfile),
 	})
 
 	defer closer()
@@ -529,7 +529,7 @@ func TestMaxMessageSize(t *testing.T) {
 
 	addr, closer := runserver(t, &smtpd.Server{
 		MaxMessageSize: 5,
-		ProtocolLogger: slog.New(slog.NewTextHandler(os.Stdout, nil)),
+		ProtocolLogger: log.New(os.Stdout, "log: ", log.Lshortfile),
 	})
 
 	defer closer()
@@ -586,7 +586,7 @@ func TestHandler(t *testing.T) {
 			}
 			return nil
 		},
-		ProtocolLogger: slog.New(slog.NewTextHandler(os.Stdout, nil)),
+		ProtocolLogger: log.New(os.Stdout, "log: ", log.Lshortfile),
 	})
 
 	defer closer()
@@ -631,7 +631,7 @@ func TestRejectHandler(t *testing.T) {
 		Handler: func(peer smtpd.Peer, env smtpd.Envelope) error {
 			return smtpd.Error{Code: 550, Message: "Rejected"}
 		},
-		ProtocolLogger: slog.New(slog.NewTextHandler(os.Stdout, nil)),
+		ProtocolLogger: log.New(os.Stdout, "log: ", log.Lshortfile),
 	})
 
 	defer closer()
@@ -674,7 +674,7 @@ func TestMaxConnections(t *testing.T) {
 
 	addr, closer := runserver(t, &smtpd.Server{
 		MaxConnections: 1,
-		ProtocolLogger: slog.New(slog.NewTextHandler(os.Stdout, nil)),
+		ProtocolLogger: log.New(os.Stdout, "log: ", log.Lshortfile),
 	})
 
 	defer closer()
@@ -696,7 +696,7 @@ func TestNoMaxConnections(t *testing.T) {
 
 	addr, closer := runserver(t, &smtpd.Server{
 		MaxConnections: -1,
-		ProtocolLogger: slog.New(slog.NewTextHandler(os.Stdout, nil)),
+		ProtocolLogger: log.New(os.Stdout, "log: ", log.Lshortfile),
 	})
 
 	defer closer()
@@ -713,7 +713,7 @@ func TestMaxRecipients(t *testing.T) {
 
 	addr, closer := runserver(t, &smtpd.Server{
 		MaxRecipients:  1,
-		ProtocolLogger: slog.New(slog.NewTextHandler(os.Stdout, nil)),
+		ProtocolLogger: log.New(os.Stdout, "log: ", log.Lshortfile),
 	})
 
 	defer closer()
@@ -744,7 +744,7 @@ func TestMaxRecipients(t *testing.T) {
 func TestInvalidHelo(t *testing.T) {
 
 	addr, closer := runserver(t, &smtpd.Server{
-		ProtocolLogger: slog.New(slog.NewTextHandler(os.Stdout, nil)),
+		ProtocolLogger: log.New(os.Stdout, "log: ", log.Lshortfile),
 	})
 
 	defer closer()
@@ -763,7 +763,7 @@ func TestInvalidHelo(t *testing.T) {
 func TestInvalidSender(t *testing.T) {
 
 	addr, closer := runserver(t, &smtpd.Server{
-		ProtocolLogger: slog.New(slog.NewTextHandler(os.Stdout, nil)),
+		ProtocolLogger: log.New(os.Stdout, "log: ", log.Lshortfile),
 	})
 
 	defer closer()
@@ -782,7 +782,7 @@ func TestInvalidSender(t *testing.T) {
 func TestInvalidRecipient(t *testing.T) {
 
 	addr, closer := runserver(t, &smtpd.Server{
-		ProtocolLogger: slog.New(slog.NewTextHandler(os.Stdout, nil)),
+		ProtocolLogger: log.New(os.Stdout, "log: ", log.Lshortfile),
 	})
 
 	defer closer()
@@ -805,7 +805,7 @@ func TestInvalidRecipient(t *testing.T) {
 func TestRCPTbeforeMAIL(t *testing.T) {
 
 	addr, closer := runserver(t, &smtpd.Server{
-		ProtocolLogger: slog.New(slog.NewTextHandler(os.Stdout, nil)),
+		ProtocolLogger: log.New(os.Stdout, "log: ", log.Lshortfile),
 	})
 
 	defer closer()
@@ -824,7 +824,7 @@ func TestRCPTbeforeMAIL(t *testing.T) {
 func TestDATAbeforeRCPT(t *testing.T) {
 
 	addr, closer := runserver(t, &smtpd.Server{
-		ProtocolLogger: slog.New(slog.NewTextHandler(os.Stdout, nil)),
+		ProtocolLogger: log.New(os.Stdout, "log: ", log.Lshortfile),
 	})
 
 	defer closer()
@@ -855,7 +855,7 @@ func TestInterruptedDATA(t *testing.T) {
 			t.Fatal("Accepted DATA despite disconnection")
 			return nil
 		},
-		ProtocolLogger: slog.New(slog.NewTextHandler(os.Stdout, nil)),
+		ProtocolLogger: log.New(os.Stdout, "log: ", log.Lshortfile),
 	})
 
 	defer closer()
@@ -893,7 +893,7 @@ func TestTimeoutClose(t *testing.T) {
 		MaxConnections: 1,
 		ReadTimeout:    time.Second,
 		WriteTimeout:   time.Second,
-		ProtocolLogger: slog.New(slog.NewTextHandler(os.Stdout, nil)),
+		ProtocolLogger: log.New(os.Stdout, "log: ", log.Lshortfile),
 	})
 
 	defer closer()
@@ -930,7 +930,7 @@ func TestTLSTimeout(t *testing.T) {
 	addr, closer := runsslserver(t, &smtpd.Server{
 		ReadTimeout:    time.Second * 2,
 		WriteTimeout:   time.Second * 2,
-		ProtocolLogger: slog.New(slog.NewTextHandler(os.Stdout, nil)),
+		ProtocolLogger: log.New(os.Stdout, "log: ", log.Lshortfile),
 	})
 
 	defer closer()
@@ -973,7 +973,7 @@ func TestTLSTimeout(t *testing.T) {
 func TestLongLine(t *testing.T) {
 
 	addr, closer := runserver(t, &smtpd.Server{
-		ProtocolLogger: slog.New(slog.NewTextHandler(os.Stdout, nil)),
+		ProtocolLogger: log.New(os.Stdout, "log: ", log.Lshortfile),
 	})
 
 	defer closer()
@@ -1012,7 +1012,7 @@ func TestXCLIENT(t *testing.T) {
 			}
 			return nil
 		},
-		ProtocolLogger: slog.New(slog.NewTextHandler(os.Stdout, nil)),
+		ProtocolLogger: log.New(os.Stdout, "log: ", log.Lshortfile),
 	})
 
 	defer closer()
@@ -1076,7 +1076,7 @@ func TestEnvelopeReceived(t *testing.T) {
 			return nil
 		},
 		ForceTLS:       true,
-		ProtocolLogger: slog.New(slog.NewTextHandler(os.Stdout, nil)),
+		ProtocolLogger: log.New(os.Stdout, "log: ", log.Lshortfile),
 	})
 
 	defer closer()
@@ -1122,7 +1122,7 @@ func TestEnvelopeReceived(t *testing.T) {
 func TestHELO(t *testing.T) {
 
 	addr, closer := runserver(t, &smtpd.Server{
-		ProtocolLogger: slog.New(slog.NewTextHandler(os.Stdout, nil)),
+		ProtocolLogger: log.New(os.Stdout, "log: ", log.Lshortfile),
 	})
 
 	defer closer()
@@ -1158,7 +1158,7 @@ func TestLOGINAuth(t *testing.T) {
 
 	addr, closer := runsslserver(t, &smtpd.Server{
 		Authenticator:  func(peer smtpd.Peer, username, password string) error { return nil },
-		ProtocolLogger: slog.New(slog.NewTextHandler(os.Stdout, nil)),
+		ProtocolLogger: log.New(os.Stdout, "log: ", log.Lshortfile),
 	})
 
 	defer closer()
@@ -1213,7 +1213,7 @@ func TestLOGINAuth(t *testing.T) {
 func TestNullSender(t *testing.T) {
 
 	addr, closer := runserver(t, &smtpd.Server{
-		ProtocolLogger: slog.New(slog.NewTextHandler(os.Stdout, nil)),
+		ProtocolLogger: log.New(os.Stdout, "log: ", log.Lshortfile),
 	})
 
 	defer closer()
@@ -1240,7 +1240,7 @@ func TestNullSender(t *testing.T) {
 func TestNoBracketsSender(t *testing.T) {
 
 	addr, closer := runserver(t, &smtpd.Server{
-		ProtocolLogger: slog.New(slog.NewTextHandler(os.Stdout, nil)),
+		ProtocolLogger: log.New(os.Stdout, "log: ", log.Lshortfile),
 	})
 
 	defer closer()
@@ -1273,7 +1273,7 @@ func TestErrors(t *testing.T) {
 
 	server := &smtpd.Server{
 		Authenticator:  func(peer smtpd.Peer, username, password string) error { return nil },
-		ProtocolLogger: slog.New(slog.NewTextHandler(os.Stdout, nil)),
+		ProtocolLogger: log.New(os.Stdout, "log: ", log.Lshortfile),
 	}
 
 	addr, closer := runserver(t, server)
@@ -1356,7 +1356,7 @@ func TestMailformedMAILFROM(t *testing.T) {
 			}
 			return nil
 		},
-		ProtocolLogger: slog.New(slog.NewTextHandler(os.Stdout, nil)),
+		ProtocolLogger: log.New(os.Stdout, "log: ", log.Lshortfile),
 	})
 
 	defer closer()
@@ -1402,7 +1402,7 @@ func TestTLSListener(t *testing.T) {
 			}
 			return nil
 		},
-		ProtocolLogger: slog.New(slog.NewTextHandler(os.Stdout, nil)),
+		ProtocolLogger: log.New(os.Stdout, "log: ", log.Lshortfile),
 	}
 
 	go func() {
@@ -1436,113 +1436,3 @@ func TestTLSListener(t *testing.T) {
 	}
 
 }
-
-func TestShutdown(t *testing.T) {
-	fmt.Println("Starting test")
-	server := &smtpd.Server{
-		ProtocolLogger: slog.New(slog.NewTextHandler(os.Stdout, nil)),
-	}
-
-	ln, err := net.Listen("tcp", "127.0.0.1:0")
-	if err != nil {
-		t.Fatalf("Listen failed: %v", err)
-	}
-
-	srvres := make(chan error)
-	go func() {
-		t.Log("Starting server")
-		srvres <- server.Serve(ln)
-	}()
-
-	// Connect a client
-	c, err := smtp.Dial(ln.Addr().String())
-	if err != nil {
-		t.Fatalf("Dial failed: %v", err)
-	}
-
-	if err := c.Hello("localhost"); err != nil {
-		t.Fatalf("HELO failed: %v", err)
-	}
-
-	// While the client connection is open, shut down the server (without
-	// waiting for it to finish)
-	err = server.Shutdown(false)
-	if err != nil {
-		t.Fatalf("Shutdown returned error: %v", err)
-	}
-
-	// Verify that Shutdown() worked by attempting to connect another client
-	_, err = smtp.Dial(ln.Addr().String())
-	if err == nil {
-		t.Fatalf("Dial did not fail as expected")
-	}
-	if _, typok := err.(*net.OpError); !typok {
-		t.Fatalf("Dial did not return net.OpError as expected: %v (%T)", err, err)
-	}
-
-	// Wait for shutdown to complete
-	shutres := make(chan error)
-	go func() {
-		t.Log("Waiting for server shutdown to finish")
-		shutres <- server.Wait()
-	}()
-
-	// Slight delay to ensure Shutdown() blocks
-	time.Sleep(250 * time.Millisecond)
-
-	// Wait() should not have returned yet due to open client conn
-	select {
-	case shuterr := <-shutres:
-		t.Fatalf("Wait() returned early w/ error: %v", shuterr)
-	default:
-	}
-
-	// Now close the client
-	t.Log("Closing client connection")
-	if err := c.Quit(); err != nil {
-		t.Fatalf("QUIT failed: %v", err)
-	}
-	c.Close()
-
-	// Wait for Wait() to return
-	t.Log("Waiting for Wait() to return")
-	select {
-	case shuterr := <-shutres:
-		if shuterr != nil {
-			t.Fatalf("Wait() returned error: %v", shuterr)
-		}
-	case <-time.After(15 * time.Second):
-		t.Fatalf("Timed out waiting for Wait() to return")
-	}
-
-	// Wait for Serve() to return
-	t.Log("Waiting for Serve() to return")
-	select {
-	case srverr := <-srvres:
-		if srverr != smtpd.ErrServerClosed {
-			t.Fatalf("Serve() returned error: %v", srverr)
-		}
-	case <-time.After(15 * time.Second):
-		t.Fatalf("Timed out waiting for Serve() to return")
-	}
-}
-
-func TestServeFailsIfShutdown(t *testing.T) {
-	server := &smtpd.Server{}
-	err := server.Shutdown(true)
-	if err != nil {
-		t.Fatalf("Shutdown() failed: %v", err)
-	}
-	err = server.Serve(nil)
-	if err != smtpd.ErrServerClosed {
-		t.Fatalf("Serve() did not return ErrServerClosed: %v", err)
-	}
-}
-
-func TestWaitFailsIfNotShutdown(t *testing.T) {
-	server := &smtpd.Server{}
-	err := server.Wait()
-	if err == nil {
-		t.Fatalf("Wait() did not fail as expected")
-	}
-}