msg.go

@@ -753,16 +753,7 @@ func (m *Msg) ToIgnoreInvalid(rcpts ...string) {
 // References:
 //   - https://datatracker.ietf.org/doc/html/rfc5322#section-3.6.3
 func (m *Msg) ToFromString(rcpts string) error {
-	src := strings.Split(rcpts, ",")
-	var dst []string
-	for _, address := range src {
-		address = strings.TrimSpace(address)
-		if address == "" {
-			continue
-		}
-		dst = append(dst, address)
-	}
-	return m.To(dst...)
+	return m.To(strings.Split(rcpts, ",")...)
 }
 
 // Cc sets one or more "CC" (carbon copy) addresses in the mail body for the Msg.

msg_test.go

@@ -5,6 +5,7 @@
 package mail
 
 import (
+	"embed"
 	"fmt"
 	"reflect"
 	"strings"
@@ -120,10 +121,8 @@ var (
 	}
 )
 
-/*
 //go:embed README.md
 var efs embed.FS
-*/
 
 func TestNewMsg(t *testing.T) {
 	t.Run("create new message", func(t *testing.T) {
@@ -627,7 +626,26 @@ func TestMsg_SetAddrHeader(t *testing.T) {
 				if err := message.SetAddrHeader(tt.header, "toni.tester@example.com"); err != nil {
 					t.Fatalf("failed to set address header, err: %s", err)
 				}
-				checkAddrHeader(t, message, tt.header, "SetAddrHeader", 0, 1, "toni.tester@example.com", "")
+				addresses, ok := message.addrHeader[tt.header]
+				if !ok {
+					t.Fatalf("failed to set address header, addrHeader field for %s is not set", tt.header)
+				}
+				if len(addresses) != 1 {
+					t.Fatalf("failed to set address header, addrHeader value count for %s is %d, want: 1",
+						tt.header, len(addresses))
+				}
+				if addresses[0].Address != "toni.tester@example.com" {
+					t.Errorf("failed to set address header, addrHeader value for %s is %s, want: %s", tt.header,
+						addresses[0].Address, "toni.tester@example.com")
+				}
+				if addresses[0].String() != "<toni.tester@example.com>" {
+					t.Errorf("failed to set address header, addrHeader value for %s is %s, want: %s", tt.header,
+						addresses[0].String(), "<toni.tester@example.com>")
+				}
+				if addresses[0].Name != "" {
+					t.Errorf("failed to set address header, addrHeader name for %s expected to be emtpy, "+
+						"got: %s", tt.header, addresses[0].Name)
+				}
 			})
 		}
 	})
@@ -641,7 +659,26 @@ func TestMsg_SetAddrHeader(t *testing.T) {
 				if err := message.SetAddrHeader(tt.header, "<toni.tester@example.com>"); err != nil {
 					t.Fatalf("failed to set address header, err: %s", err)
 				}
-				checkAddrHeader(t, message, tt.header, "SetAddrHeader", 0, 1, "toni.tester@example.com", "")
+				addresses, ok := message.addrHeader[tt.header]
+				if !ok {
+					t.Fatalf("failed to set address header, addrHeader field for %s is not set", tt.header)
+				}
+				if len(addresses) != 1 {
+					t.Fatalf("failed to set address header, addrHeader value count for %s is %d, want: 1",
+						tt.header, len(addresses))
+				}
+				if addresses[0].Address != "toni.tester@example.com" {
+					t.Errorf("failed to set address header, addrHeader value for %s is %s, want: %s", tt.header,
+						addresses[0].Address, "toni.tester@example.com")
+				}
+				if addresses[0].String() != "<toni.tester@example.com>" {
+					t.Errorf("failed to set address header, addrHeader value for %s is %s, want: %s", tt.header,
+						addresses[0].String(), "<toni.tester@example.com>")
+				}
+				if addresses[0].Name != "" {
+					t.Errorf("failed to set address header, addrHeader name for %s expected to be emtpy, "+
+						"got: %s", tt.header, addresses[0].Name)
+				}
 			})
 		}
 	})
@@ -656,8 +693,26 @@ func TestMsg_SetAddrHeader(t *testing.T) {
 					"toni.tester@example.com")); err != nil {
 					t.Fatalf("failed to set address header, err: %s", err)
 				}
-				checkAddrHeader(t, message, tt.header, "SetAddrHeader", 0, 1,
-					"toni.tester@example.com", "Toni Tester")
+				addresses, ok := message.addrHeader[tt.header]
+				if !ok {
+					t.Fatalf("failed to set address header, addrHeader field for %s is not set", tt.header)
+				}
+				if len(addresses) != 1 {
+					t.Fatalf("failed to set address header, addrHeader value count for %s is %d, want: 1",
+						tt.header, len(addresses))
+				}
+				if addresses[0].Address != "toni.tester@example.com" {
+					t.Errorf("failed to set address header, addrHeader value for %s is %s, want: %s", tt.header,
+						addresses[0].Address, "toni.tester@example.com")
+				}
+				if addresses[0].String() != `"Toni Tester" <toni.tester@example.com>` {
+					t.Errorf("failed to set address header, addrHeader value for %s is %s, want: %s", tt.header,
+						addresses[0].String(), `"Toni Tester" <toni.tester@example.com>`)
+				}
+				if addresses[0].Name != "Toni Tester" {
+					t.Errorf("failed to set address header, addrHeader name for %s expected to be %s, "+
+						"got: %s", tt.header, "Toni Tester", addresses[0].Name)
+				}
 			})
 		}
 	})
@@ -677,8 +732,38 @@ func TestMsg_SetAddrHeader(t *testing.T) {
 					"tina.tester@example.com"); err != nil {
 					t.Fatalf("failed to set address header, err: %s", err)
 				}
-				checkAddrHeader(t, message, tt.header, "SetAddrHeader", 0, 2, "toni.tester@example.com", "")
-				checkAddrHeader(t, message, tt.header, "SetAddrHeader", 1, 2, "tina.tester@example.com", "")
+				addresses, ok := message.addrHeader[tt.header]
+				if !ok {
+					t.Fatalf("failed to set address header, addrHeader field for %s is not set", tt.header)
+				}
+				if len(addresses) != 2 {
+					t.Fatalf("failed to set address header, addrHeader value count for %s is %d, want: 2",
+						tt.header, len(addresses))
+				}
+				if addresses[0].Address != "toni.tester@example.com" {
+					t.Errorf("failed to set address header, addrHeader value for %s is %s, want: %s", tt.header,
+						addresses[0].Address, "toni.tester@example.com")
+				}
+				if addresses[0].String() != "<toni.tester@example.com>" {
+					t.Errorf("failed to set address header, addrHeader value for %s is %s, want: %s", tt.header,
+						addresses[0].String(), "<toni.tester@example.com>")
+				}
+				if addresses[0].Name != "" {
+					t.Errorf("failed to set address header, addrHeader name for %s expected to be emtpy, "+
+						"got: %s", tt.header, addresses[0].Name)
+				}
+				if addresses[1].Address != "tina.tester@example.com" {
+					t.Errorf("failed to set address header, addrHeader value for %s is %s, want: %s", tt.header,
+						addresses[1].Address, "tina.tester@example.com")
+				}
+				if addresses[1].String() != "<tina.tester@example.com>" {
+					t.Errorf("failed to set address header, addrHeader value for %s is %s, want: %s", tt.header,
+						addresses[1].String(), "<tina.tester@example.com>")
+				}
+				if addresses[1].Name != "" {
+					t.Errorf("failed to set address header, addrHeader name for %s expected to be emtpy, "+
+						"got: %s", tt.header, addresses[1].Name)
+				}
 			})
 		}
 	})
@@ -691,7 +776,26 @@ func TestMsg_SetAddrHeader(t *testing.T) {
 			"tina.tester@example.com"); err != nil {
 			t.Fatalf("failed to set address header, err: %s", err)
 		}
-		checkAddrHeader(t, message, HeaderFrom, "SetAddrHeader", 0, 1, "toni.tester@example.com", "")
+		addresses, ok := message.addrHeader[HeaderFrom]
+		if !ok {
+			t.Fatalf("failed to set address header, addrHeader field for %s is not set", HeaderFrom)
+		}
+		if len(addresses) != 1 {
+			t.Fatalf("failed to set address header, addrHeader value count for From is: %d, want: 1",
+				len(addresses))
+		}
+		if addresses[0].Address != "toni.tester@example.com" {
+			t.Errorf("failed to set address header, addrHeader value for %s is %s, want: %s", HeaderFrom,
+				addresses[0].Address, "toni.tester@example.com")
+		}
+		if addresses[0].String() != "<toni.tester@example.com>" {
+			t.Errorf("failed to set address header, addrHeader value for %s is %s, want: %s", HeaderFrom,
+				addresses[0].String(), "<toni.tester@example.com>")
+		}
+		if addresses[0].Name != "" {
+			t.Errorf("failed to set address header, addrHeader name for %s expected to be emtpy, "+
+				"got: %s", HeaderFrom, addresses[0].Name)
+		}
 	})
 	t.Run("SetAddrHeader with addrHeader map is nil", func(t *testing.T) {
 		message := NewMsg()
@@ -703,7 +807,26 @@ func TestMsg_SetAddrHeader(t *testing.T) {
 			"tina.tester@example.com"); err != nil {
 			t.Fatalf("failed to set address header, err: %s", err)
 		}
-		checkAddrHeader(t, message, HeaderFrom, "SetAddrHeader", 0, 1, "toni.tester@example.com", "")
+		addresses, ok := message.addrHeader[HeaderFrom]
+		if !ok {
+			t.Fatalf("failed to set address header, addrHeader field for %s is not set", HeaderFrom)
+		}
+		if len(addresses) != 1 {
+			t.Fatalf("failed to set address header, addrHeader value count for From is: %d, want: 1",
+				len(addresses))
+		}
+		if addresses[0].Address != "toni.tester@example.com" {
+			t.Errorf("failed to set address header, addrHeader value for %s is %s, want: %s", HeaderFrom,
+				addresses[0].Address, "toni.tester@example.com")
+		}
+		if addresses[0].String() != "<toni.tester@example.com>" {
+			t.Errorf("failed to set address header, addrHeader value for %s is %s, want: %s", HeaderFrom,
+				addresses[0].String(), "<toni.tester@example.com>")
+		}
+		if addresses[0].Name != "" {
+			t.Errorf("failed to set address header, addrHeader name for %s expected to be emtpy, "+
+				"got: %s", HeaderFrom, addresses[0].Name)
+		}
 	})
 	t.Run("SetAddrHeader with invalid address", func(t *testing.T) {
 		for _, tt := range addrHeaderTests {
@@ -729,8 +852,26 @@ func TestMsg_SetAddrHeaderIgnoreInvalid(t *testing.T) {
 					t.Fatal("message is nil")
 				}
 				message.SetAddrHeaderIgnoreInvalid(tt.header, "toni.tester@example.com")
-				checkAddrHeader(t, message, tt.header, "SetAddrHeaderIgnoreInvalid", 0, 1,
-					"toni.tester@example.com", "")
+				addresses, ok := message.addrHeader[tt.header]
+				if !ok {
+					t.Fatalf("failed to set address header, addrHeader field for %s is not set", tt.header)
+				}
+				if len(addresses) != 1 {
+					t.Fatalf("failed to set address header, addrHeader value count for %s is %d, want: 1",
+						tt.header, len(addresses))
+				}
+				if addresses[0].Address != "toni.tester@example.com" {
+					t.Errorf("failed to set address header, addrHeader value for %s is %s, want: %s", tt.header,
+						addresses[0].Address, "toni.tester@example.com")
+				}
+				if addresses[0].String() != "<toni.tester@example.com>" {
+					t.Errorf("failed to set address header, addrHeader value for %s is %s, want: %s", tt.header,
+						addresses[0].String(), "<toni.tester@example.com>")
+				}
+				if addresses[0].Name != "" {
+					t.Errorf("failed to set address header, addrHeader name for %s expected to be emtpy, "+
+						"got: %s", tt.header, addresses[0].Name)
+				}
 			})
 		}
 	})
@@ -742,8 +883,26 @@ func TestMsg_SetAddrHeaderIgnoreInvalid(t *testing.T) {
 					t.Fatal("message is nil")
 				}
 				message.SetAddrHeaderIgnoreInvalid(tt.header, "<toni.tester@example.com>")
-				checkAddrHeader(t, message, tt.header, "SetAddrHeaderIgnoreInvalid", 0, 1,
-					"toni.tester@example.com", "")
+				addresses, ok := message.addrHeader[tt.header]
+				if !ok {
+					t.Fatalf("failed to set address header, addrHeader field for %s is not set", tt.header)
+				}
+				if len(addresses) != 1 {
+					t.Fatalf("failed to set address header, addrHeader value count for %s is %d, want: 1",
+						tt.header, len(addresses))
+				}
+				if addresses[0].Address != "toni.tester@example.com" {
+					t.Errorf("failed to set address header, addrHeader value for %s is %s, want: %s", tt.header,
+						addresses[0].Address, "toni.tester@example.com")
+				}
+				if addresses[0].String() != "<toni.tester@example.com>" {
+					t.Errorf("failed to set address header, addrHeader value for %s is %s, want: %s", tt.header,
+						addresses[0].String(), "<toni.tester@example.com>")
+				}
+				if addresses[0].Name != "" {
+					t.Errorf("failed to set address header, addrHeader name for %s expected to be emtpy, "+
+						"got: %s", tt.header, addresses[0].Name)
+				}
 			})
 		}
 	})
@@ -761,10 +920,38 @@ func TestMsg_SetAddrHeaderIgnoreInvalid(t *testing.T) {
 				}
 				message.SetAddrHeaderIgnoreInvalid(tt.header, "toni.tester@example.com",
 					"tina.tester@example.com")
-				checkAddrHeader(t, message, tt.header, "SetAddrHeaderIgnoreInvalid", 0, 2,
-					"toni.tester@example.com", "")
-				checkAddrHeader(t, message, tt.header, "SetAddrHeaderIgnoreInvalid", 1, 2,
-					"tina.tester@example.com", "")
+				addresses, ok := message.addrHeader[tt.header]
+				if !ok {
+					t.Fatalf("failed to set address header, addrHeader field for %s is not set", tt.header)
+				}
+				if len(addresses) != 2 {
+					t.Fatalf("failed to set address header, addrHeader value count for %s is %d, want: 2",
+						tt.header, len(addresses))
+				}
+				if addresses[0].Address != "toni.tester@example.com" {
+					t.Errorf("failed to set address header, addrHeader value for %s is %s, want: %s", tt.header,
+						addresses[0].Address, "toni.tester@example.com")
+				}
+				if addresses[0].String() != "<toni.tester@example.com>" {
+					t.Errorf("failed to set address header, addrHeader value for %s is %s, want: %s", tt.header,
+						addresses[0].String(), "<toni.tester@example.com>")
+				}
+				if addresses[0].Name != "" {
+					t.Errorf("failed to set address header, addrHeader name for %s expected to be emtpy, "+
+						"got: %s", tt.header, addresses[0].Name)
+				}
+				if addresses[1].Address != "tina.tester@example.com" {
+					t.Errorf("failed to set address header, addrHeader value for %s is %s, want: %s", tt.header,
+						addresses[1].Address, "tina.tester@example.com")
+				}
+				if addresses[1].String() != "<tina.tester@example.com>" {
+					t.Errorf("failed to set address header, addrHeader value for %s is %s, want: %s", tt.header,
+						addresses[1].String(), "<tina.tester@example.com>")
+				}
+				if addresses[1].Name != "" {
+					t.Errorf("failed to set address header, addrHeader name for %s expected to be emtpy, "+
+						"got: %s", tt.header, addresses[1].Name)
+				}
 			})
 		}
 	})
@@ -781,11 +968,39 @@ func TestMsg_SetAddrHeaderIgnoreInvalid(t *testing.T) {
 					t.Fatal("message is nil")
 				}
 				message.SetAddrHeaderIgnoreInvalid(tt.header, "toni.tester@example.com",
-					"invalid", "tina.tester@example.com")
-				checkAddrHeader(t, message, tt.header, "SetAddrHeaderIgnoreInvalid", 0, 2,
-					"toni.tester@example.com", "")
-				checkAddrHeader(t, message, tt.header, "SetAddrHeaderIgnoreInvalid", 1, 2,
-					"tina.tester@example.com", "")
+					"invalid", "valid@address.tld")
+				addresses, ok := message.addrHeader[tt.header]
+				if !ok {
+					t.Fatalf("failed to set address header, addrHeader field for %s is not set", tt.header)
+				}
+				if len(addresses) != 2 {
+					t.Fatalf("failed to set address header, addrHeader value count for %s is %d, want: 2",
+						tt.header, len(addresses))
+				}
+				if addresses[0].Address != "toni.tester@example.com" {
+					t.Errorf("failed to set address header, addrHeader value for %s is %s, want: %s", tt.header,
+						addresses[0].Address, "toni.tester@example.com")
+				}
+				if addresses[0].String() != "<toni.tester@example.com>" {
+					t.Errorf("failed to set address header, addrHeader value for %s is %s, want: %s", tt.header,
+						addresses[0].String(), "<toni.tester@example.com>")
+				}
+				if addresses[0].Name != "" {
+					t.Errorf("failed to set address header, addrHeader name for %s expected to be emtpy, "+
+						"got: %s", tt.header, addresses[0].Name)
+				}
+				if addresses[1].Address != "valid@address.tld" {
+					t.Errorf("failed to set address header, addrHeader value for %s is %s, want: %s", tt.header,
+						addresses[1].Address, "valid@address.tld")
+				}
+				if addresses[1].String() != "<valid@address.tld>" {
+					t.Errorf("failed to set address header, addrHeader value for %s is %s, want: %s", tt.header,
+						addresses[1].String(), "<valid@address.tld>")
+				}
+				if addresses[1].Name != "" {
+					t.Errorf("failed to set address header, addrHeader name for %s expected to be emtpy, "+
+						"got: %s", tt.header, addresses[1].Name)
+				}
 			})
 		}
 	})
@@ -796,7 +1011,26 @@ func TestMsg_SetAddrHeaderIgnoreInvalid(t *testing.T) {
 		}
 		message.addrHeader = nil
 		message.SetAddrHeaderIgnoreInvalid(HeaderFrom, "toni.tester@example.com", "tina.tester@example.com")
-		checkAddrHeader(t, message, HeaderFrom, "SetAddrHeaderIgnoreInvalid", 0, 1, "toni.tester@example.com", "")
+		addresses, ok := message.addrHeader[HeaderFrom]
+		if !ok {
+			t.Fatalf("failed to set address header, addrHeader field for %s is not set", HeaderFrom)
+		}
+		if len(addresses) != 1 {
+			t.Fatalf("failed to set address header, addrHeader value count for From is: %d, want: 1",
+				len(addresses))
+		}
+		if addresses[0].Address != "toni.tester@example.com" {
+			t.Errorf("failed to set address header, addrHeader value for %s is %s, want: %s", HeaderFrom,
+				addresses[0].Address, "toni.tester@example.com")
+		}
+		if addresses[0].String() != "<toni.tester@example.com>" {
+			t.Errorf("failed to set address header, addrHeader value for %s is %s, want: %s", HeaderFrom,
+				addresses[0].String(), "<toni.tester@example.com>")
+		}
+		if addresses[0].Name != "" {
+			t.Errorf("failed to set address header, addrHeader name for %s expected to be emtpy, "+
+				"got: %s", HeaderFrom, addresses[0].Name)
+		}
 	})
 	t.Run("SetAddrHeaderIgnoreInvalid with invalid addresses only", func(t *testing.T) {
 		for _, tt := range addrHeaderTests {
@@ -828,7 +1062,24 @@ func TestMsg_EnvelopeFrom(t *testing.T) {
 		if err := message.EnvelopeFrom("toni.tester@example.com"); err != nil {
 			t.Fatalf("failed to set envelope from: %s", err)
 		}
-		checkAddrHeader(t, message, HeaderEnvelopeFrom, "EnvelopeFrom", 0, 1, "toni.tester@example.com", "")
+		addresses, ok := message.addrHeader[HeaderEnvelopeFrom]
+		if !ok {
+			t.Fatalf("failed to set envelope from, addrHeader field is not set")
+		}
+		if len(addresses) != 1 {
+			t.Fatalf("failed to set envelope from, addrHeader value count is: %d, want: 1", len(addresses))
+		}
+		if addresses[0].Address != "toni.tester@example.com" {
+			t.Errorf("failed to set envelope from, addrHeader value is %s, want: %s", addresses[0].Address,
+				"toni.tester@example.com")
+		}
+		if addresses[0].String() != "<toni.tester@example.com>" {
+			t.Errorf("failed to set envelope from, addrHeader value is %s, want: %s", addresses[0].String(),
+				"<toni.tester@example.com>")
+		}
+		if addresses[0].Name != "" {
+			t.Errorf("failed to set envelope from, addrHeader name is %s, want: empty", addresses[0].Name)
+		}
 	})
 	t.Run("EnvelopeFrom with invalid address", func(t *testing.T) {
 		message := NewMsg()
@@ -859,7 +1110,25 @@ func TestMsg_EnvelopeFromFormat(t *testing.T) {
 		if err := message.EnvelopeFromFormat("Toni Tester", "toni.tester@example.com"); err != nil {
 			t.Fatalf("failed to set envelope From: %s", err)
 		}
-		checkAddrHeader(t, message, HeaderEnvelopeFrom, "FromFormat", 0, 1, "toni.tester@example.com", "Toni Tester")
+		addresses, ok := message.addrHeader[HeaderEnvelopeFrom]
+		if !ok {
+			t.Fatalf("failed to set envelope From, addrHeader field is not set")
+		}
+		if len(addresses) != 1 {
+			t.Fatalf("failed to set envelope From, addrHeader value count is: %d, want: 1", len(addresses))
+		}
+		if addresses[0].Address != "toni.tester@example.com" {
+			t.Errorf("failed to set envelope From, addrHeader value is %s, want: %s", addresses[0].Address,
+				"toni.tester@example.com")
+		}
+		if addresses[0].String() != `"Toni Tester" <toni.tester@example.com>` {
+			t.Errorf("failed to set envelope From, addrHeader value is %s, want: %s", addresses[0].String(),
+				"<toni.tester@example.com>")
+		}
+		if addresses[0].Name != "Toni Tester" {
+			t.Errorf("failed to set envelope From, addrHeader name is %s, want: %s", addresses[0].Name,
+				"Toni Tester")
+		}
 	})
 	t.Run("EnvelopeFromFormat with invalid address", func(t *testing.T) {
 		message := NewMsg()
@@ -890,7 +1159,24 @@ func TestMsg_From(t *testing.T) {
 		if err := message.From("toni.tester@example.com"); err != nil {
 			t.Fatalf("failed to set From: %s", err)
 		}
-		checkAddrHeader(t, message, HeaderFrom, "From", 0, 1, "toni.tester@example.com", "")
+		addresses, ok := message.addrHeader[HeaderFrom]
+		if !ok {
+			t.Fatalf("failed to set From, addrHeader field is not set")
+		}
+		if len(addresses) != 1 {
+			t.Fatalf("failed to set From, addrHeader value count is: %d, want: 1", len(addresses))
+		}
+		if addresses[0].Address != "toni.tester@example.com" {
+			t.Errorf("failed to set From, addrHeader value is %s, want: %s", addresses[0].Address,
+				"toni.tester@example.com")
+		}
+		if addresses[0].String() != "<toni.tester@example.com>" {
+			t.Errorf("failed to set From, addrHeader value is %s, want: %s", addresses[0].String(),
+				"<toni.tester@example.com>")
+		}
+		if addresses[0].Name != "" {
+			t.Errorf("failed to set From, addrHeader name is %s, want: empty", addresses[0].Name)
+		}
 	})
 	t.Run("From with invalid address", func(t *testing.T) {
 		message := NewMsg()
@@ -938,7 +1224,25 @@ func TestMsg_FromFormat(t *testing.T) {
 		if err := message.FromFormat("Toni Tester", "toni.tester@example.com"); err != nil {
 			t.Fatalf("failed to set From: %s", err)
 		}
-		checkAddrHeader(t, message, HeaderFrom, "FromFormat", 0, 1, "toni.tester@example.com", "Toni Tester")
+		addresses, ok := message.addrHeader[HeaderFrom]
+		if !ok {
+			t.Fatalf("failed to set From, addrHeader field is not set")
+		}
+		if len(addresses) != 1 {
+			t.Fatalf("failed to set From, addrHeader value count is: %d, want: 1", len(addresses))
+		}
+		if addresses[0].Address != "toni.tester@example.com" {
+			t.Errorf("failed to set From, addrHeader value is %s, want: %s", addresses[0].Address,
+				"toni.tester@example.com")
+		}
+		if addresses[0].String() != `"Toni Tester" <toni.tester@example.com>` {
+			t.Errorf("failed to set From, addrHeader value is %s, want: %s", addresses[0].String(),
+				"<toni.tester@example.com>")
+		}
+		if addresses[0].Name != "Toni Tester" {
+			t.Errorf("failed to set From, addrHeader name is %s, want: %s", addresses[0].Name,
+				"Toni Tester")
+		}
 	})
 	t.Run("FromFormat with invalid address", func(t *testing.T) {
 		message := NewMsg()
@@ -969,7 +1273,24 @@ func TestMsg_To(t *testing.T) {
 		if err := message.To("toni.tester@example.com"); err != nil {
 			t.Fatalf("failed to set To: %s", err)
 		}
-		checkAddrHeader(t, message, HeaderTo, "To", 0, 1, "toni.tester@example.com", "")
+		addresses, ok := message.addrHeader[HeaderTo]
+		if !ok {
+			t.Fatalf("failed to set To, addrHeader field is not set")
+		}
+		if len(addresses) != 1 {
+			t.Fatalf("failed to set To, addrHeader value count is: %d, want: 1", len(addresses))
+		}
+		if addresses[0].Address != "toni.tester@example.com" {
+			t.Errorf("failed to set To, addrHeader value is %s, want: %s", addresses[0].Address,
+				"toni.tester@example.com")
+		}
+		if addresses[0].String() != "<toni.tester@example.com>" {
+			t.Errorf("failed to set To, addrHeader value is %s, want: %s", addresses[0].String(),
+				"<toni.tester@example.com>")
+		}
+		if addresses[0].Name != "" {
+			t.Errorf("failed to set To, addrHeader name is %s, want: empty", addresses[0].Name)
+		}
 	})
 	t.Run("To with multiple valid addresses", func(t *testing.T) {
 		message := NewMsg()
@@ -979,8 +1300,35 @@ func TestMsg_To(t *testing.T) {
 		if err := message.To("toni.tester@example.com", "tina.tester@example.com"); err != nil {
 			t.Fatalf("failed to set To: %s", err)
 		}
-		checkAddrHeader(t, message, HeaderTo, "To", 0, 2, "toni.tester@example.com", "")
-		checkAddrHeader(t, message, HeaderTo, "To", 1, 2, "tina.tester@example.com", "")
+		addresses, ok := message.addrHeader[HeaderTo]
+		if !ok {
+			t.Fatalf("failed to set To, addrHeader field is not set")
+		}
+		if len(addresses) != 2 {
+			t.Fatalf("failed to set To, addrHeader value count is: %d, want: 2", len(addresses))
+		}
+		if addresses[0].Address != "toni.tester@example.com" {
+			t.Errorf("failed to set To, addrHeader value is %s, want: %s", addresses[0].Address,
+				"toni.tester@example.com")
+		}
+		if addresses[0].String() != "<toni.tester@example.com>" {
+			t.Errorf("failed to set To, addrHeader value is %s, want: %s", addresses[0].String(),
+				"<toni.tester@example.com>")
+		}
+		if addresses[0].Name != "" {
+			t.Errorf("failed to set To, addrHeader name is %s, want: empty", addresses[0].Name)
+		}
+		if addresses[1].Address != "tina.tester@example.com" {
+			t.Errorf("failed to set To, addrHeader value is %s, want: %s", addresses[1].Address,
+				"tina.tester@example.com")
+		}
+		if addresses[1].String() != "<tina.tester@example.com>" {
+			t.Errorf("failed to set To, addrHeader value is %s, want: %s", addresses[1].String(),
+				"<tina.tester@example.com>")
+		}
+		if addresses[1].Name != "" {
+			t.Errorf("failed to set To, addrHeader name is %s, want: empty", addresses[1].Name)
+		}
 	})
 	t.Run("To with invalid address", func(t *testing.T) {
 		message := NewMsg()
@@ -1031,8 +1379,35 @@ func TestMsg_AddTo(t *testing.T) {
 		if err := message.AddTo("tina.tester@example.com"); err != nil {
 			t.Fatalf("failed to set additional To: %s", err)
 		}
-		checkAddrHeader(t, message, HeaderTo, "AddTo", 0, 2, "toni.tester@example.com", "")
-		checkAddrHeader(t, message, HeaderTo, "AddTo", 1, 2, "tina.tester@example.com", "")
+		addresses, ok := message.addrHeader[HeaderTo]
+		if !ok {
+			t.Fatalf("failed to set To, addrHeader field is not set")
+		}
+		if len(addresses) != 2 {
+			t.Fatalf("failed to set additional To, addrHeader value count is: %d, want: 1", len(addresses))
+		}
+		if addresses[0].Address != "toni.tester@example.com" {
+			t.Errorf("failed to set To, addrHeader value is %s, want: %s", addresses[0].Address,
+				"toni.tester@example.com")
+		}
+		if addresses[0].String() != "<toni.tester@example.com>" {
+			t.Errorf("failed to set To, addrHeader value is %s, want: %s", addresses[0].String(),
+				"<toni.tester@example.com>")
+		}
+		if addresses[0].Name != "" {
+			t.Errorf("failed to set To, addrHeader name is %s, want: empty", addresses[0].Name)
+		}
+		if addresses[1].Address != "tina.tester@example.com" {
+			t.Errorf("failed to set additional To, addrHeader value is %s, want: %s", addresses[1].Address,
+				"tina.tester@example.com")
+		}
+		if addresses[1].String() != "<tina.tester@example.com>" {
+			t.Errorf("failed to set additional To, addrHeader value is %s, want: %s", addresses[1].String(),
+				"<tina.tester@example.com>")
+		}
+		if addresses[1].Name != "" {
+			t.Errorf("failed to set additional To, addrHeader name is %s, want: empty", addresses[1].Name)
+		}
 	})
 	t.Run("AddTo with invalid address", func(t *testing.T) {
 		message := NewMsg()
@@ -1045,7 +1420,13 @@ func TestMsg_AddTo(t *testing.T) {
 		if err := message.AddTo("invalid"); err == nil {
 			t.Errorf("AddTo should fail with invalid address")
 		}
-		checkAddrHeader(t, message, HeaderTo, "AddTo", 0, 1, "toni.tester@example.com", "")
+		addresses, ok := message.addrHeader[HeaderTo]
+		if !ok {
+			t.Fatalf("failed to set To, addrHeader field is not set")
+		}
+		if len(addresses) != 1 {
+			t.Fatalf("failed to set To, addrHeader value count is: %d, want: 1", len(addresses))
+		}
 	})
 }
 
@@ -1061,8 +1442,36 @@ func TestMsg_AddToFormat(t *testing.T) {
 		if err := message.AddToFormat("Tina Tester", "tina.tester@example.com"); err != nil {
 			t.Fatalf("failed to set additional To: %s", err)
 		}
-		checkAddrHeader(t, message, HeaderTo, "AddToFormat", 0, 2, "toni.tester@example.com", "")
-		checkAddrHeader(t, message, HeaderTo, "AddToFormat", 1, 2, "tina.tester@example.com", "Tina Tester")
+		addresses, ok := message.addrHeader[HeaderTo]
+		if !ok {
+			t.Fatalf("failed to set To, addrHeader field is not set")
+		}
+		if len(addresses) != 2 {
+			t.Fatalf("failed to set additional To, addrHeader value count is: %d, want: 1", len(addresses))
+		}
+		if addresses[0].Address != "toni.tester@example.com" {
+			t.Errorf("failed to set To, addrHeader value is %s, want: %s", addresses[0].Address,
+				"toni.tester@example.com")
+		}
+		if addresses[0].String() != "<toni.tester@example.com>" {
+			t.Errorf("failed to set To, addrHeader value is %s, want: %s", addresses[0].String(),
+				"<toni.tester@example.com>")
+		}
+		if addresses[0].Name != "" {
+			t.Errorf("failed to set To, addrHeader name is %s, want: empty", addresses[0].Name)
+		}
+		if addresses[1].Address != "tina.tester@example.com" {
+			t.Errorf("failed to set additional To, addrHeader value is %s, want: %s", addresses[1].Address,
+				"tina.tester@example.com")
+		}
+		if addresses[1].String() != `"Tina Tester" <tina.tester@example.com>` {
+			t.Errorf("failed to set additional To, addrHeader value is %s, want: %s", addresses[1].String(),
+				"<tina.tester@example.com>")
+		}
+		if addresses[1].Name != "Tina Tester" {
+			t.Errorf("failed to set additional To, addrHeader name is %s, want: %s", addresses[1].Name,
+				"Tina Tester")
+		}
 	})
 	t.Run("AddToFormat with invalid address", func(t *testing.T) {
 		message := NewMsg()
@@ -1075,93 +1484,18 @@ func TestMsg_AddToFormat(t *testing.T) {
 		if err := message.AddToFormat("Invalid", "invalid"); err == nil {
 			t.Errorf("AddToFormat should fail with invalid address")
 		}
-		checkAddrHeader(t, message, HeaderTo, "AddToFormat", 0, 1, "toni.tester@example.com", "")
+		addresses, ok := message.addrHeader[HeaderTo]
+		if !ok {
+			t.Fatalf("failed to set To, addrHeader field is not set")
+		}
+		if len(addresses) != 1 {
+			t.Fatalf("failed to set To, addrHeader value count is: %d, want: 1", len(addresses))
+		}
 	})
 }
 
 func TestMsg_ToIgnoreInvalid(t *testing.T) {
-	t.Run("ToIgnoreInvalid with valid address", func(t *testing.T) {
-		message := NewMsg()
-		if message == nil {
-			t.Fatal("message is nil")
-		}
-		message.ToIgnoreInvalid("toni.tester@example.com")
-		checkAddrHeader(t, message, HeaderTo, "ToIgnoreInvalid", 0, 1, "toni.tester@example.com", "")
-	})
-	t.Run("ToIgnoreInvalid with invalid address", func(t *testing.T) {
-		message := NewMsg()
-		if message == nil {
-			t.Fatal("message is nil")
-		}
-		message.ToIgnoreInvalid("invalid")
-		addresses, ok := message.addrHeader[HeaderTo]
-		if !ok {
-			t.Fatalf("failed to set ToIgnoreInvalid, addrHeader field is not set")
-		}
-		if len(addresses) != 0 {
-			t.Fatalf("failed to set ToIgnoreInvalid, addrHeader value count is: %d, want: 0", len(addresses))
-		}
-	})
-	t.Run("ToIgnoreInvalid with valid and invalid addresses", func(t *testing.T) {
-		message := NewMsg()
-		if message == nil {
-			t.Fatal("message is nil")
-		}
-		message.ToIgnoreInvalid("toni.tester@example.com", "invalid", "tina.tester@example.com")
-		checkAddrHeader(t, message, HeaderTo, "ToIgnoreInvalid", 0, 2, "toni.tester@example.com", "")
-		checkAddrHeader(t, message, HeaderTo, "ToIgnoreInvalid", 1, 2, "tina.tester@example.com", "")
-	})
-}
 
-func TestMsg_ToFromString(t *testing.T) {
-	t.Run("ToFromString with valid addresses", func(t *testing.T) {
-		message := NewMsg()
-		if message == nil {
-			t.Fatal("message is nil")
-		}
-		if err := message.ToFromString(`toni.tester@example.com,<tina.tester@example.com>`); err != nil {
-			t.Fatalf("failed to set ToFromString: %s", err)
-		}
-		checkAddrHeader(t, message, HeaderTo, "ToFromString", 0, 2, "toni.tester@example.com", "")
-		checkAddrHeader(t, message, HeaderTo, "ToFromString", 1, 2, "tina.tester@example.com", "")
-	})
-	t.Run("ToFromString with valid addresses and empty fields", func(t *testing.T) {
-		message := NewMsg()
-		if message == nil {
-			t.Fatal("message is nil")
-		}
-		if err := message.ToFromString(`toni.tester@example.com ,,<tina.tester@example.com>`); err != nil {
-			t.Fatalf("failed to set ToFromString: %s", err)
-		}
-		checkAddrHeader(t, message, HeaderTo, "ToFromString", 0, 2, "toni.tester@example.com", "")
-		checkAddrHeader(t, message, HeaderTo, "ToFromString", 1, 2, "tina.tester@example.com", "")
-	})
-}
-
-// checkAddrHeader validates a single email address in the AddrHeader of a message.
-func checkAddrHeader(t *testing.T, message *Msg, header AddrHeader, fn string, field, wantFields int,
-	wantMail, wantName string) {
-	t.Helper()
-	addresses, ok := message.addrHeader[header]
-	if !ok {
-		t.Fatalf("failed to set %s, addrHeader field is not set", fn)
-	}
-	if len(addresses) != wantFields {
-		t.Fatalf("failed to set %s, addrHeader value count is: %d, want: %d", fn, len(addresses), field)
-	}
-	if addresses[field].Address != wantMail {
-		t.Errorf("failed to set %s, addrHeader value is %s, want: %s", fn, addresses[field].Address, wantMail)
-	}
-	wantString := fmt.Sprintf(`<%s>`, wantMail)
-	if wantName != "" {
-		wantString = fmt.Sprintf(`%q <%s>`, wantName, wantMail)
-	}
-	if addresses[field].String() != wantString {
-		t.Errorf("failed to set %s, addrHeader value is %s, want: %s", fn, addresses[field].String(), wantString)
-	}
-	if addresses[field].Name != wantName {
-		t.Errorf("failed to set %s, addrHeader name is %s, want: %s", fn, addresses[field].Name, wantName)
-	}
 }
 
 /*