fix: keep a comma inside an address name

email.go

@@ -85,10 +85,49 @@ func (tr *trimReader) Read(buf []byte) (int, error) {
 	return n, err
 }
 
+// splitAddressList splits on commas that separate addresses. A comma inside a
+// quoted string or a comment is part of that address.
+func splitAddressList(s string) []string {
+	var parts []string
+	var b strings.Builder
+	var quote, escape bool
+	var paren int
+	for _, r := range s {
+		if escape {
+			b.WriteRune(r)
+			escape = false
+			continue
+		}
+		if quote && r == '\\' {
+			b.WriteRune(r)
+			escape = true
+			continue
+		}
+		if r == '"' {
+			quote = !quote
+			b.WriteRune(r)
+			continue
+		}
+		if !quote && r == '(' {
+			paren++
+		} else if !quote && r == ')' && paren > 0 {
+			paren--
+		}
+		if r == ',' && !quote && paren == 0 {
+			parts = append(parts, b.String())
+			b.Reset()
+			continue
+		}
+		b.WriteRune(r)
+	}
+	parts = append(parts, b.String())
+	return parts
+}
+
 func handleAddressList(v []string) []string {
 	res := []string{}
 	for _, a := range v {
-		w := strings.Split(a, ",")
+		w := splitAddressList(a)
 		for _, addr := range w {
 			decodedAddr, err := (&mime.WordDecoder{}).DecodeHeader(strings.TrimSpace(addr))
 			if err == nil {

email_test.go

@@ -554,6 +554,20 @@ This is a test message!`)
 	}
 }
 
+func TestAddressListCommaInsideName(t *testing.T) {
+	raw := []byte("From: a@b.com\r\nTo: \"Doe, John\" <john@example.com>, Jane <jane@example.com>\r\nCc: (Doe, John) <john@example.com>\r\nSubject: hi\r\nContent-Type: text/plain\r\n\r\nhello\r\n")
+	e, err := NewEmailFromReader(bytes.NewReader(raw))
+	if err != nil {
+		t.Fatal(err)
+	}
+	if len(e.To) != 2 || e.To[0] != `"Doe, John" <john@example.com>` || e.To[1] != "Jane <jane@example.com>" {
+		t.Fatalf("To: got %#v", e.To)
+	}
+	if len(e.Cc) != 1 || e.Cc[0] != "(Doe, John) <john@example.com>" {
+		t.Fatalf("Cc: got %#v", e.Cc)
+	}
+}
+
 func TestNonMultipartEmailFromReader(t *testing.T) {
 	ex := &Email{
 		Text:    []byte("This is a test message!"),
@@ -728,7 +742,7 @@ TGV0J3MganVzdCBwcmV0ZW5kIHRoaXMgaXMgcmF3IEpQRUcgZGF0YS4=
 	}
 }
 
-func ExampleGmail() {
+func Example_gmail() {
 	e := NewEmail()
 	e.From = "Jordan Wright <test@gmail.com>"
 	e.To = []string{"test@example.com"}
@@ -740,7 +754,7 @@ func ExampleGmail() {
 	e.Send("smtp.gmail.com:587", smtp.PlainAuth("", e.From, "password123", "smtp.gmail.com"))
 }
 
-func ExampleAttach() {
+func Example_attach() {
 	e := NewEmail()
 	e.AttachFile("test.txt")
 }