GODT-2181: Empty but not nil address from API

pkg/message/build.go

@@ -381,6 +381,18 @@ func writeMultipartEncryptedRFC822(header message.Header, body []byte) ([]byte,
 	return buf.Bytes(), nil
 }
 
+func addressEmpty(address *mail.Address) bool {
+	if address == nil {
+		return true
+	}
+
+	if address.Name == "" && address.Address == "" {
+		return true
+	}
+
+	return false
+}
+
 func getMessageHeader(msg proton.Message, opts JobOptions) message.Header { //nolint:funlen
 	hdr := toMessageHeader(msg.ParsedHeaders)
 
@@ -390,12 +402,14 @@ func getMessageHeader(msg proton.Message, opts JobOptions) message.Header { //no
 	}
 
 	// mail.Address.String() will RFC2047-encode if necessary.
-	if msg.Sender != nil {
+	if !addressEmpty(msg.Sender) {
 		hdr.Set("From", msg.Sender.String())
 	}
 
 	if len(msg.ReplyTos) > 0 {
-		hdr.Set("Reply-To", toAddressList(msg.ReplyTos))
+		if !(len(msg.ReplyTos) == 1 && addressEmpty(msg.ReplyTos[0])) {
+			hdr.Set("Reply-To", toAddressList(msg.ReplyTos))
+		}
 	}
 
 	if len(msg.ToList) > 0 {

tests/features/imap/message/import.feature

@@ -136,7 +136,7 @@ Feature: IMAP import messages
       | foo@example.com | bridgetest@pm.test | Hello   | Hello |
     And IMAP client "1" sees 0 messages in "Inbox"
 
-  Scenario Outline: Import message without sender
+  Scenario Outline: Import message without sender to <mailbox>
     When IMAP client "1" appends the following message to "<mailbox>":
       """
       To: Lionel Richie <lionel@richie.com>