diff --git a/pkg/msghub/hub_test.go b/pkg/msghub/hub_test.go
index ad4c0c0..a8688b2 100644
--- a/pkg/msghub/hub_test.go
+++ b/pkg/msghub/hub_test.go
@@ -81,7 +81,7 @@ func TestHubZeroLen(t *testing.T) {
 	hub := New(0, extension.NewHost())
 	go hub.Start(ctx)
 	m := event.MessageMetadata{}
-	for i := 0; i < 100; i++ {
+	for range 100 {
 		hub.Dispatch(m)
 	}
 	// Ensures Hub doesn't panic
@@ -93,7 +93,7 @@ func TestHubZeroListeners(t *testing.T) {
 	hub := New(5, extension.NewHost())
 	go hub.Start(ctx)
 	m := event.MessageMetadata{}
-	for i := 0; i < 100; i++ {
+	for range 100 {
 		hub.Dispatch(m)
 	}
 	// Ensures Hub doesn't panic
@@ -178,7 +178,7 @@ func TestHubHistoryReplay(t *testing.T) {
 
 	// Broadcast 3 messages with no listeners
 	msgs := make([]event.MessageMetadata, 3)
-	for i := 0; i < len(msgs); i++ {
+	for i := range msgs {
 		msgs[i] = event.MessageMetadata{
 			Subject: fmt.Sprintf("subj %v", i),
 		}
@@ -203,7 +203,7 @@ func TestHubHistoryReplay(t *testing.T) {
 		t.Fatal("Timeout:", l2)
 	}
 
-	for i := 0; i < len(msgs); i++ {
+	for i := range msgs {
 		got := l2.messages[i].Subject
 		want := msgs[i].Subject
 		if got != want {
@@ -222,7 +222,7 @@ func TestHubHistoryDelete(t *testing.T) {
 
 	// Broadcast 3 messages with no listeners
 	msgs := make([]event.MessageMetadata, 3)
-	for i := 0; i < len(msgs); i++ {
+	for i := range msgs {
 		msgs[i] = event.MessageMetadata{
 			Mailbox: "hub",
 			ID:      strconv.Itoa(i),
@@ -253,7 +253,7 @@ func TestHubHistoryDelete(t *testing.T) {
 	}
 
 	want := []string{"subj 0", "subj 2"}
-	for i := 0; i < len(want); i++ {
+	for i := range want {
 		got := l2.messages[i].Subject
 		if got != want[i] {
 			t.Errorf("msg[%v].Subject == %q, want %q", i, got, want[i])
@@ -271,7 +271,7 @@ func TestHubHistoryReplayWrap(t *testing.T) {
 
 	// Broadcast more messages than the hub can hold
 	msgs := make([]event.MessageMetadata, 20)
-	for i := 0; i < len(msgs); i++ {
+	for i := range msgs {
 		msgs[i] = event.MessageMetadata{
 			Subject: fmt.Sprintf("subj %v", i),
 		}
@@ -296,7 +296,7 @@ func TestHubHistoryReplayWrap(t *testing.T) {
 		t.Fatal("Timeout:", l2)
 	}
 
-	for i := 0; i < 5; i++ {
+	for i := range 5 {
 		got := l2.messages[i].Subject
 		want := msgs[i+15].Subject
 		if got != want {
@@ -326,7 +326,7 @@ func TestHubHistoryReplayWrapAfterDelete(t *testing.T) {
 
 	// Broadcast more messages than the hub can hold.
 	msgs := make([]event.MessageMetadata, 10)
-	for i := 0; i < len(msgs); i++ {
+	for i := range msgs {
 		msgs[i] = event.MessageMetadata{
 			Mailbox: "first",
 			ID:      strconv.Itoa(i),
@@ -343,7 +343,7 @@ func TestHubHistoryReplayWrapAfterDelete(t *testing.T) {
 	hub.Delete("first", "7")
 
 	// Broadcast another set of messages.
-	for i := 0; i < len(msgs); i++ {
+	for i := range msgs {
 		msgs[i] = event.MessageMetadata{
 			Mailbox: "second",
 			ID:      strconv.Itoa(i),
diff --git a/pkg/policy/address.go b/pkg/policy/address.go
index 1f55957..e19c2ff 100644
--- a/pkg/policy/address.go
+++ b/pkg/policy/address.go
@@ -274,7 +274,7 @@ func parseEmailAddress(address string) (local string, domain string, err error)
 	inCharQuote := false
 	inStringQuote := false
 LOOP:
-	for i := 0; i < len(address); i++ {
+	for i := range len(address) {
 		c := address[i]
 		switch {
 		case ('a' <= c && c <= 'z') || ('A' <= c && c <= 'Z'):
@@ -380,7 +380,7 @@ func parseMailboxName(localPart string) (result string, err error) {
 	}
 	result = strings.ToLower(localPart)
 	invalid := make([]byte, 0, 10)
-	for i := 0; i < len(result); i++ {
+	for i := range len(result) {
 		c := result[i]
 		switch {
 		case 'a' <= c && c <= 'z':
diff --git a/pkg/storage/mem/store_test.go b/pkg/storage/mem/store_test.go
index 79c2ad9..f56a4b1 100644
--- a/pkg/storage/mem/store_test.go
+++ b/pkg/storage/mem/store_test.go
@@ -37,7 +37,7 @@ func TestMaxSize(t *testing.T) {
 	for _, mailbox := range boxes {
 		go func(mailbox string) {
 			size := int64(0)
-			for i := 0; i < n; i++ {
+			for range n {
 				_, nbytes := test.DeliverToStore(t, s, mailbox, "subject", time.Now())
 				size += nbytes
 			}
diff --git a/pkg/test/storage_suite.go b/pkg/test/storage_suite.go
index 00c3ad7..0a41311 100644
--- a/pkg/test/storage_suite.go
+++ b/pkg/test/storage_suite.go
@@ -139,7 +139,7 @@ func testMetadata(s storeSuite) {
 // testContent generates some binary content and makes sure it is correctly retrieved.
 func testContent(s storeSuite) {
 	content := make([]byte, 5000)
-	for i := 0; i < len(content); i++ {
+	for i := range content {
 		content[i] = byte(i % 256)
 	}
 	mailbox := "testmailbox"
@@ -388,7 +388,7 @@ func testMsgCap(s storeSuite) {
 	mbCap := 10
 	mailbox := "captain"
 
-	for i := 0; i < 20; i++ {
+	for i := range 20 {
 		subj := fmt.Sprintf("subject %v", i)
 		DeliverToStore(s.T, s.store, mailbox, subj, time.Now())
 		msgs, err := s.store.GetMessages(mailbox)
@@ -401,10 +401,7 @@ func testMsgCap(s storeSuite) {
 		}
 
 		// Check that the first (oldest) message is correct.
-		first := i - mbCap + 1
-		if first < 0 {
-			first = 0
-		}
+		first := max(i-mbCap+1, 0)
 		firstSubj := fmt.Sprintf("subject %v", first)
 		if firstSubj != msgs[0].Subject() {
 			s.Errorf("Got subject %q, wanted first subject: %q", msgs[0].Subject(), firstSubj)
@@ -415,7 +412,7 @@ func testMsgCap(s storeSuite) {
 // testNoMsgCap verfies a cap of 0 is not enforced.
 func testNoMsgCap(s storeSuite) {
 	mailbox := "captain"
-	for i := 0; i < 20; i++ {
+	for i := range 20 {
 		subj := fmt.Sprintf("subject %v", i)
 		DeliverToStore(s.T, s.store, mailbox, subj, time.Now())
 		GetAndCountMessages(s.T, s.store, mailbox, i+1)