From b4fb05127933965bfc1757f8a2b0507238a7b7a6 Mon Sep 17 00:00:00 2001
From: Daniel Jagszent <daniel@jagszent.de>
Date: Mon, 13 Mar 2023 20:07:27 +0100
Subject: [PATCH] chore: make integration tests more robust

---
 Makefile                                    |  8 +++---
 integration/docker/syslog-ng.conf           |  1 +
 integration/go.mod                          |  4 +--
 integration/mta/mock/mta.go                 | 18 ++++++++------
 integration/mta/mock/mta.sh                 |  2 --
 integration/mta/postfix/mta.sh              |  2 --
 integration/mta/script.sh                   |  1 +
 integration/mta/sendmail/mta.sh             |  8 +++---
 integration/mta/sendmail/sendmail.cf        | 18 +++++++-------
 integration/runner/config.go                | 23 +++++++++++++++---
 integration/runner/main.go                  |  6 ++++-
 integration/runner/mta.go                   | 18 ++++++++------
 integration/runner/runner.go                | 27 +++++++++------------
 integration/testcase.go                     |  8 +++---
 integration/tests/body/test.go              |  2 --
 integration/tests/header/test.go            |  2 --
 integration/tests/mail-from/change.testcase |  3 +++
 integration/tests/mail-from/test.go         |  9 +++++--
 integration/tests/rcpt-to/add.testcase      |  4 +++
 integration/tests/rcpt-to/change.testcase   |  3 +++
 integration/tests/rcpt-to/test.go           | 10 ++++++--
 21 files changed, 107 insertions(+), 70 deletions(-)
 create mode 100644 integration/tests/mail-from/change.testcase
 create mode 100644 integration/tests/rcpt-to/add.testcase
 create mode 100644 integration/tests/rcpt-to/change.testcase

diff --git a/Makefile b/Makefile
index 76e862a..ae8ed8a 100644
--- a/Makefile
+++ b/Makefile
@@ -1,8 +1,8 @@
-GO_MILTER_DIR := $(shell go list -f '{{.Dir}}' github.com/d--j/go-milter)
+GO_MILTER_INTEGRATION_DIR := $(shell cd integration && go list -f '{{.Dir}}' github.com/d--j/go-milter/integration)
 
 integration:
-	docker build -q --progress=plain -t go-milter-integration "$(GO_MILTER_DIR)/integration/docker" && \
-	docker run --rm -w /usr/src/root/integration -v $(PWD):/usr/src/root go-milter-integration \
-	go run github.com/d--j/go-milter/integration/runner -filter '.*' ./tests
+	docker build -q --progress=plain -t go-milter-integration "$(GO_MILTER_INTEGRATION_DIR)/docker" && \
+	docker run --rm --hostname=mx.example.com -w /usr/src/root/integration -v $(PWD):/usr/src/root go-milter-integration \
+	go run github.com/d--j/go-milter/integration/runner -filter '.*' -mtaFilter '.*' ./tests
 
 .PHONY: integration
diff --git a/integration/docker/syslog-ng.conf b/integration/docker/syslog-ng.conf
index 63a99a3..217f0f4 100644
--- a/integration/docker/syslog-ng.conf
+++ b/integration/docker/syslog-ng.conf
@@ -2,6 +2,7 @@
 @include "scl.conf"
 
 source s_local {
+  unix-stream("/dev/log");
   internal();
 };
 
diff --git a/integration/go.mod b/integration/go.mod
index a4ff759..2106e72 100644
--- a/integration/go.mod
+++ b/integration/go.mod
@@ -3,17 +3,17 @@ module github.com/d--j/go-milter/integration
 go 1.18
 
 require (
-	github.com/d--j/go-milter v0.6.0
+	github.com/d--j/go-milter v0.6.5
 	github.com/emersion/go-message v0.16.0
 	github.com/emersion/go-sasl v0.0.0-20200509203442-7bfe0ed36a21
 	github.com/emersion/go-smtp v0.16.0
+	golang.org/x/text v0.7.0
 	golang.org/x/tools v0.1.12
 )
 
 require (
 	github.com/emersion/go-textwrapper v0.0.0-20200911093747-65d896831594 // indirect
 	golang.org/x/net v0.7.0 // indirect
-	golang.org/x/text v0.7.0 // indirect
 )
 
 replace github.com/d--j/go-milter => ../
diff --git a/integration/mta/mock/mta.go b/integration/mta/mock/mta.go
index 0609174..31a8fcd 100644
--- a/integration/mta/mock/mta.go
+++ b/integration/mta/mock/mta.go
@@ -46,8 +46,9 @@ type Backend struct {
 
 func (bkd *Backend) NewSession(conn *smtp.Conn) (smtp.Session, error) {
 	macros := milter.NewMacroBag()
-	macros.Set(milter.MacroMTAFullyQualifiedDomainName, "localhost.local")
-	macros.Set(milter.MacroDaemonName, "localhost.local")
+	macros.Set(milter.MacroMTAVersion, "MOCK-SMTP 0.0.0")
+	macros.Set(milter.MacroMTAFQDN, "localhost.local")
+	macros.Set(milter.MacroDaemonName, "mock-smtp")
 	macros.Set(milter.MacroIfName, "eth99")
 	addr, _, err := net.SplitHostPort(conn.Conn().LocalAddr().String())
 	if err != nil {
@@ -289,21 +290,22 @@ func (s *Session) Data(r io.Reader) error {
 	for _, act := range modActions {
 		switch act.Type {
 		case milter.ActionChangeFrom:
-			log.Printf("[%s] ACT = ActionChangeFrom <%s> %s", s.queueId, act.From, act.FromArgs)
-			s.MailFrom = act.From
+			log.Printf("[%s] ACT = ActionChangeFrom %s %s", s.queueId, act.From, act.FromArgs)
+			s.MailFrom = milter.RemoveAngle(act.From)
 			s.MailFromArgs = act.FromArgs
 		case milter.ActionDelRcpt:
-			log.Printf("[%s] ACT = ActionDelRcpt <%s>", s.queueId, act.Rcpt)
+			log.Printf("[%s] ACT = ActionDelRcpt %s", s.queueId, act.Rcpt)
+			rcpt := milter.RemoveAngle(act.Rcpt)
 		again:
 			for i, r := range s.Recipients {
-				if act.Rcpt == r.Addr {
+				if rcpt == r.Addr {
 					s.Recipients = append(s.Recipients[:i], s.Recipients[i+1:]...)
 					goto again
 				}
 			}
 		case milter.ActionAddRcpt:
-			log.Printf("[%s] ACT = ActionAddRcpt <%s> %s", s.queueId, act.Rcpt, act.RcptArgs)
-			s.Recipients = append(s.Recipients, Rcpt{Addr: act.Rcpt, Args: act.RcptArgs})
+			log.Printf("[%s] ACT = ActionAddRcpt %s %s", s.queueId, act.Rcpt, act.RcptArgs)
+			s.Recipients = append(s.Recipients, Rcpt{Addr: milter.RemoveAngle(act.Rcpt), Args: act.RcptArgs})
 		case milter.ActionReplaceBody:
 			log.Printf("[%s] ACT = ActionReplaceBody %q", s.queueId, act.Body)
 			replacedBody = append(replacedBody, act.Body...)
diff --git a/integration/mta/mock/mta.sh b/integration/mta/mock/mta.sh
index cf285f2..40b79f5 100755
--- a/integration/mta/mock/mta.sh
+++ b/integration/mta/mock/mta.sh
@@ -16,14 +16,12 @@ if [ "tags" = "$1" ]; then
 fi
 
 if [ "start" = "$1" ]; then
-  shift
   parse_args "$@"
   go build -o "$SCRATCH_DIR/mta.exe" -v "$SCRIPT_DIR"
   exec "$SCRATCH_DIR/mta.exe" -mta ":$MTA_PORT" -next ":$RECEIVER_PORT" -milter ":$MILTER_PORT" -cert "$SCRATCH_DIR/../cert.pem" -key "$SCRATCH_DIR/../key.pem"
 fi
 
 if [ "stop" = "$1" ]; then
-  shift
   parse_args "$@"
   exit 0
 fi
diff --git a/integration/mta/postfix/mta.sh b/integration/mta/postfix/mta.sh
index 88a837b..f0a52ad 100755
--- a/integration/mta/postfix/mta.sh
+++ b/integration/mta/postfix/mta.sh
@@ -137,7 +137,6 @@ setup_chroot() {
 }
 
 if [ "start" = "$1" ]; then
-  shift
   parse_args "$@"
   mkdir "$SCRATCH_DIR/conf" "$SCRATCH_DIR/conf/sasl" "$SCRATCH_DIR/data" "$SCRATCH_DIR/queue" || die "could not create $SCRATCH_DIR/{conf,data,queue}"
   render_template <"$SCRIPT_DIR/main.cf" >"$SCRATCH_DIR/conf/main.cf" || die "could not create $SCRATCH_DIR/conf/main.cf"
@@ -156,7 +155,6 @@ if [ "start" = "$1" ]; then
 fi
 
 if [ "stop" = "$1" ]; then
-  shift
   parse_args "$@"
   sudo -n -- postfix -v -c "$SCRATCH_DIR/conf" stop
   exit 0
diff --git a/integration/mta/script.sh b/integration/mta/script.sh
index 51072f9..b5324f2 100644
--- a/integration/mta/script.sh
+++ b/integration/mta/script.sh
@@ -12,6 +12,7 @@ usage() {
 }
 
 parse_args() {
+  shift
   while [ $# -gt 0 ]; do
     case $1 in
     -mtaPort)
diff --git a/integration/mta/sendmail/mta.sh b/integration/mta/sendmail/mta.sh
index 6c2e778..c3e3855 100755
--- a/integration/mta/sendmail/mta.sh
+++ b/integration/mta/sendmail/mta.sh
@@ -14,24 +14,24 @@ if [ "tags" = "$1" ]; then
   echo "auth-no"
   #echo "auth-plain"
   echo "tls-no"
-  #echo "tls-starttls"
+  echo "tls-starttls"
   exit 0
 fi
 
 if [ "start" = "$1" ]; then
-  shift
   parse_args "$@"
+  cp "$SCRATCH_DIR/../cert.pem" "$SCRATCH_DIR/cert.pem" || die "could not create $SCRATCH_DIR/cert.pem"
+  cp "$SCRATCH_DIR/../key.pem" "$SCRATCH_DIR/key.pem" || die "could not create $SCRATCH_DIR/key.pem"
   render_template <"$SCRIPT_DIR/sendmail.cf" >"$SCRATCH_DIR/sendmail.cf" || die "could not create $SCRATCH_DIR/sendmail.cf"
   mkdir "${SCRATCH_DIR}/mqueue" || die "could not create $SCRATCH_DIR/mqueue"
   sudo -n -- chown smmta:smmsp "${SCRATCH_DIR}/mqueue" || die "could not chown $SCRATCH_DIR/mqueue"
   sudo -n -- chmod u=rwx,g=rs,o= "${SCRATCH_DIR}/mqueue" || die "could not chmod $SCRATCH_DIR/mqueue"
-  sudo -n -- syslog-ng || die "could not start syslog-ng"
+  sudo -n -- syslog-ng --no-caps || die "could not start syslog-ng"
   sudo -n -- /usr/libexec/sendmail/sendmail -bd "-C${SCRATCH_DIR}/sendmail.cf"
   exit 0
 fi
 
 if [ "stop" = "$1" ]; then
-  shift
   parse_args "$@"
   # echo "SHUTDOWN" > "${SCRATCH_DIR}/smcontrol"
   kill "$(head -n1 "${SCRATCH_DIR}/sendmail.pid")"
diff --git a/integration/mta/sendmail/sendmail.cf b/integration/mta/sendmail/sendmail.cf
index d668d7e..127c716 100644
--- a/integration/mta/sendmail/sendmail.cf
+++ b/integration/mta/sendmail/sendmail.cf
@@ -101,7 +101,7 @@ Fw/etc/mail/local-host-names %[^\#]
 
 # my official domain name
 # ... define this only if sendmail cannot automatically determine your domain
-#Dj$w.Foo.COM
+Djmx.example.com
 
 # host/domain names ending with a token in class P are canonical
 CP.
@@ -253,7 +253,7 @@ O UseErrorsTo=False
 #O UseCompressedIPv6Addresses
 
 # log level
-O LogLevel=9
+O LogLevel=50
 
 # send to me too, even in an alias expansion?
 O MeToo=True
@@ -299,8 +299,8 @@ O MaxRunnersPerQueue=5
 # shall we sort the queue by hostname first?
 #O QueueSortOrder=priority
 
-# increase milter log level (breaks sendmail?)
-#O Milter.LogLevel=99
+# increase milter log level
+O Milter.LogLevel=50
 
 # minimum time in queue before retry
 #O MinQueueAge=30m
@@ -570,19 +570,19 @@ O ProcessTitlePrefix=MTA
 
 
 # CA directory
-#O CACertPath
+O CACertPath=/etc/ssl/certs/
 # CA file
-#O CACertFile
+O CACertFile=%{SCRATCH_DIR}/cert.pem
 # Server Cert
-#O ServerCertFile
+O ServerCertFile=%{SCRATCH_DIR}/cert.pem
 # Server private key
-#O ServerKeyFile
+O ServerKeyFile=%{SCRATCH_DIR}/key.pem
 # Client Cert
 #O ClientCertFile
 # Client private key
 #O ClientKeyFile
 # File containing certificate revocation lists
-#O CRLFile
+O CRLFile=/dev/null
 # DHParameters (only required if DSA/DH is used)
 #O DHParameters
 # Random data source (required for systems without /dev/urandom under OpenSSL)
diff --git a/integration/runner/config.go b/integration/runner/config.go
index fb14edd..ea3cf97 100644
--- a/integration/runner/config.go
+++ b/integration/runner/config.go
@@ -49,6 +49,8 @@ func ParseConfig() *Config {
 	flag.UintVar(&milterPort, "milterPort", 34126, "`port` for test milter servers (1024 < port < 65536")
 	filter := ""
 	flag.StringVar(&filter, "filter", "", "regexp `pattern` to filter testcases")
+	mtaFilter := ""
+	flag.StringVar(&mtaFilter, "mtaFilter", "", "regexp `pattern` to filter MTAs")
 	flag.Usage = func() {
 		fmt.Fprintf(flag.CommandLine.Output(), "Usage of %s:\n", os.Args[0])
 		flag.PrintDefaults()
@@ -62,6 +64,13 @@ func ParseConfig() *Config {
 	if err != nil {
 		LevelOneLogger.Fatal(err)
 	}
+	if mtaFilter == "" {
+		mtaFilter = ".*"
+	}
+	mtaFilterRe, err := regexp.Compile(mtaFilter)
+	if err != nil {
+		LevelOneLogger.Fatal(err)
+	}
 	config := Config{
 		MtaStartPort: uint16(mtaPort),
 		ReceiverPort: uint16(receiverPort),
@@ -97,13 +106,19 @@ func ParseConfig() *Config {
 	if mtas == nil {
 		LevelOneLogger.Fatalf("did not find any MTAs")
 	}
-	if mtaPort+uint(len(mtas)) > math.MaxUint16 {
+	var filteredMtas []string
+	for _, m := range mtas {
+		if mtaFilterRe.MatchString(m) {
+			filteredMtas = append(filteredMtas, m)
+		}
+	}
+	if mtaPort+uint(len(filteredMtas)) > math.MaxUint16 {
 		LevelOneLogger.Fatal("too many MTAs, pick a lower -mtaPort")
 	}
-	if overlap(receiverPort, receiverPort, mtaPort, mtaPort+uint(len(mtas))) {
+	if overlap(receiverPort, receiverPort, mtaPort, mtaPort+uint(len(filteredMtas))) {
 		LevelOneLogger.Fatal("-receiverPort and -mtaPort overlap")
 	}
-	if overlap(milterPort, milterPort, mtaPort, mtaPort+uint(len(mtas))) {
+	if overlap(milterPort, milterPort, mtaPort, mtaPort+uint(len(filteredMtas))) {
 		LevelOneLogger.Fatal("-milterPort and -mtaPort overlap")
 	}
 	if overlap(receiverPort, receiverPort, milterPort, milterPort) {
@@ -111,7 +126,7 @@ func ParseConfig() *Config {
 	}
 	var dirs []*TestDir
 	var tests []*TestCase
-	for _, p := range mtas {
+	for _, p := range filteredMtas {
 		mta, err := NewMTA(p, uint16(mtaPort), &config)
 		mtaPort++
 		if err != nil {
diff --git a/integration/runner/main.go b/integration/runner/main.go
index 845a0b0..0055e3f 100644
--- a/integration/runner/main.go
+++ b/integration/runner/main.go
@@ -18,5 +18,9 @@ func main() {
 	}
 	defer receiver.Cleanup()
 	runner := NewRunner(config, &receiver)
-	runner.Run()
+	if !runner.Run() {
+		receiver.Cleanup()
+		config.Cleanup()
+		os.Exit(1)
+	}
 }
diff --git a/integration/runner/mta.go b/integration/runner/mta.go
index 6da20c6..e2ca5f8 100644
--- a/integration/runner/mta.go
+++ b/integration/runner/mta.go
@@ -65,8 +65,12 @@ func (m *MTA) MarkFailedTest() {
 }
 
 func (m *MTA) Start() error {
+	err := os.Chmod(m.path, 0755)
+	if err != nil {
+		return err
+	}
 	m.dir = path.Join(m.config.ScratchDir, fmt.Sprintf("mta-%d", m.Port))
-	err := os.Mkdir(m.dir, 0755)
+	err = os.Mkdir(m.dir, 0755)
 	if err != nil && !os.IsExist(err) {
 		return err
 	}
@@ -92,13 +96,13 @@ func (m *MTA) Start() error {
 		b, err := m.cmd.CombinedOutput()
 		failed := !IsExpectedExitErr(err)
 		if failed {
-			LevelTwoLogger.Print(err)
+			LevelOneLogger.Print(err)
 		}
 		m.m.Lock()
 		failedTest := m.failedTest
 		m.m.Unlock()
-		if failed || failedTest {
-			LevelTwoLogger.Printf("MTA %s\n%s", m.path, b)
+		if failed || failedTest && len(b) > 0 {
+			LevelOneLogger.Printf("MTA %s output\n%s", m.path, b)
 		}
 		m.wg.Done()
 		cancel()
@@ -109,7 +113,7 @@ func (m *MTA) Start() error {
 		m.Stop()
 		return err
 	}
-	LevelTwoLogger.Printf("MTA %s ready", m.path)
+	LevelOneLogger.Printf("MTA %s ready", m.path)
 	return nil
 }
 
@@ -131,8 +135,8 @@ func (m *MTA) Stop() {
 		m.m.Lock()
 		failedTest := m.failedTest
 		m.m.Unlock()
-		if failedTest {
-			LevelTwoLogger.Printf("MTA %s stop\n%s", m.path, b)
+		if failedTest && len(b) > 0 {
+			LevelOneLogger.Printf("MTA %s stop output\n%s", m.path, b)
 		}
 	})
 }
diff --git a/integration/runner/runner.go b/integration/runner/runner.go
index db1146e..25851dc 100644
--- a/integration/runner/runner.go
+++ b/integration/runner/runner.go
@@ -1,8 +1,6 @@
 package main
 
 import (
-	"os"
-
 	"github.com/d--j/go-milter/integration"
 )
 
@@ -18,7 +16,7 @@ func NewRunner(config *Config, receiver *Receiver) *Runner {
 	}
 }
 
-func (r *Runner) Run() {
+func (r *Runner) Run() bool {
 	var prevMta *MTA
 	var prevDir *TestDir
 	defer func() {
@@ -39,7 +37,8 @@ func (r *Runner) Run() {
 			LevelOneLogger.Print(dir.MTA)
 			prevMta = dir.MTA
 			if err := dir.MTA.Start(); err != nil {
-				LevelTwoLogger.Fatal(err)
+				LevelTwoLogger.Printf("ERR starting MTA %v", err)
+				return false
 			}
 		}
 		prevDir = dir
@@ -53,7 +52,8 @@ func (r *Runner) Run() {
 				}
 				continue
 			}
-			LevelTwoLogger.Fatal(err)
+			LevelTwoLogger.Printf("ERR starting milter %v", err)
+			return false
 		}
 		for _, t := range dir.Tests {
 			i++
@@ -63,13 +63,12 @@ func (r *Runner) Run() {
 			}
 			code, message, step, err := t.Send(t.TestCase.InputSteps, dir.MTA.Port)
 			if err != nil {
-				prevMta.MarkFailedTest()
-				prevMta.Stop()
-				LevelThreeLogger.Fatal(err)
+				t.MarkFailed("ERR %v", err)
+				return false
 			}
 			if !t.TestCase.Decision.Compare(code, message, step) {
 				r.receiver.IgnoreMessages()
-				t.MarkFailed("%03d/%03d NOK DECISION %s != %d %s @%s", i, tests, t.TestCase.Decision, code, message, step)
+				t.MarkFailed("NOK DECISION %s != %d %s @%s", t.TestCase.Decision, code, message, step)
 				continue
 			}
 			if t.TestCase.ExpectsOutput() {
@@ -79,15 +78,15 @@ func (r *Runner) Run() {
 				if !ok {
 					if t.parent.MTA.HasTag("mta-sendmail") {
 						if integration.CompareOutputSendmail(t.TestCase.Output, output) {
-							t.MarkOk("%03d/%03d OK (sendmail) %s", i, tests, diff)
+							t.MarkOk("OK (sendmail) %s", diff)
 							continue
 						}
 					}
-					t.MarkFailed("%03d/%03d NOK OUTPUT %s", i, tests, diff)
+					t.MarkFailed("NOK OUTPUT %sRECEIVED OUTPUT\n%s", diff, output)
 					continue
 				}
 			}
-			t.MarkOk("%03d/%03d OK", i, tests)
+			t.MarkOk("OK")
 		}
 		prevDir.Stop()
 	}
@@ -103,7 +102,5 @@ func (r *Runner) Run() {
 		}
 	}
 	LevelOneLogger.Printf("%d tests done: %d OK %d skipped %d failed", len(r.config.Tests), numOk, numSkipped, numFailed)
-	if numFailed > 0 {
-		os.Exit(1)
-	}
+	return numFailed == 0
 }
diff --git a/integration/testcase.go b/integration/testcase.go
index 20bfcca..dbc28e8 100644
--- a/integration/testcase.go
+++ b/integration/testcase.go
@@ -131,22 +131,22 @@ func (o *Output) String() string {
 	var b strings.Builder
 	if o.From != nil {
 		b.WriteString("FROM\n")
-		b.WriteString(fmt.Sprintf("- <%s> %s\n", o.From.Addr, o.From.Arg))
+		b.WriteString(fmt.Sprintf("<%s> %s\n", o.From.Addr, o.From.Arg))
 	}
 	if o.To != nil {
 		b.WriteString("TO\n")
 		for _, t := range o.To {
-			b.WriteString(fmt.Sprintf("- <%s> %s\n", t.Addr, t.Arg))
+			b.WriteString(fmt.Sprintf("<%s> %s\n", t.Addr, t.Arg))
 		}
 	}
 	if o.Header != nil {
 		b.WriteString("HEADER\n")
-		b.WriteString(fmt.Sprintf("- %q\n", o.Header))
+		b.WriteString(fmt.Sprintf("%q\n", o.Header))
 
 	}
 	if o.Body != nil {
 		b.WriteString("BODY\n")
-		b.WriteString(fmt.Sprintf("- %q\n", o.Body))
+		b.WriteString(fmt.Sprintf("%q\n", o.Body))
 	}
 	return b.String()
 }
diff --git a/integration/tests/body/test.go b/integration/tests/body/test.go
index 4931ad4..8bba731 100644
--- a/integration/tests/body/test.go
+++ b/integration/tests/body/test.go
@@ -1,5 +1,3 @@
-//go:build: auth-no
-
 package main
 
 import (
diff --git a/integration/tests/header/test.go b/integration/tests/header/test.go
index a4c14ca..0e48b85 100644
--- a/integration/tests/header/test.go
+++ b/integration/tests/header/test.go
@@ -1,5 +1,3 @@
-//go:build: auth-no
-
 package main
 
 import (
diff --git a/integration/tests/mail-from/change.testcase b/integration/tests/mail-from/change.testcase
new file mode 100644
index 0000000..ff623a1
--- /dev/null
+++ b/integration/tests/mail-from/change.testcase
@@ -0,0 +1,3 @@
+FROM <change@example.com>
+DECISION ACCEPT
+FROM <another@example.com> *
diff --git a/integration/tests/mail-from/test.go b/integration/tests/mail-from/test.go
index 8520a66..bcf6a89 100644
--- a/integration/tests/mail-from/test.go
+++ b/integration/tests/mail-from/test.go
@@ -1,5 +1,3 @@
-//go:build: auth-no
-
 package main
 
 import (
@@ -26,6 +24,13 @@ func main() {
 		if trx.MailFrom.Addr == "quarantine@example.com" {
 			return mailfilter.QuarantineResponse("test"), nil
 		}
+		if trx.MailFrom.Addr == "change@example.com" {
+			trx.MailFrom.Addr = "another@example.com"
+			// Sendmail might break when you do not null this out
+			if trx.MTA.IsSendmail() {
+				trx.MailFrom.Args = ""
+			}
+		}
 		return mailfilter.Accept, nil
 	}, mailfilter.WithDecisionAt(mailfilter.DecisionAtMailFrom))
 }
diff --git a/integration/tests/rcpt-to/add.testcase b/integration/tests/rcpt-to/add.testcase
new file mode 100644
index 0000000..db49663
--- /dev/null
+++ b/integration/tests/rcpt-to/add.testcase
@@ -0,0 +1,4 @@
+TO <add@example.com>
+DECISION ACCEPT
+TO <add@example.com> *
+TO <another@example.com> *
diff --git a/integration/tests/rcpt-to/change.testcase b/integration/tests/rcpt-to/change.testcase
new file mode 100644
index 0000000..983e0b0
--- /dev/null
+++ b/integration/tests/rcpt-to/change.testcase
@@ -0,0 +1,3 @@
+TO <change@example.com>
+DECISION ACCEPT
+TO <another@example.com> *
diff --git a/integration/tests/rcpt-to/test.go b/integration/tests/rcpt-to/test.go
index 4da98ac..fc7f424 100644
--- a/integration/tests/rcpt-to/test.go
+++ b/integration/tests/rcpt-to/test.go
@@ -1,5 +1,3 @@
-//go:build: auth-no
-
 package main
 
 import (
@@ -26,6 +24,14 @@ func main() {
 		if trx.HasRcptTo("quarantine@example.com") {
 			return mailfilter.QuarantineResponse("test"), nil
 		}
+		if trx.HasRcptTo("add@example.com") {
+			trx.AddRcptTo("another@example.com", "")
+		}
+		if trx.HasRcptTo("change@example.com") {
+			trx.DelRcptTo("change@example.com")
+			// Sendmail does not like setting ESMTP args, so we do not set any
+			trx.AddRcptTo("another@example.com", "")
+		}
 		return mailfilter.Accept, nil
 		// the decision is done at the DATA command but the mock server sends the DATA response before we can intercept
 		// so the testcases allow the rejection at any step, not only at "DATA".