lib-smtp: smtp-client-connection - Retain the host name in the connec…

…tion label after DNS lookup.

src/lib-smtp/smtp-client-connection.c

@@ -1488,6 +1488,9 @@ static void
 smtp_client_connection_connect_next_ip(struct smtp_client_connection *conn)
 {
 	const struct ip_addr *ip, *my_ip = &conn->set.my_ip;
+	const char *conn_name = (conn->host_is_ip ? NULL :
+				 t_strdup_printf("%s:%u", conn->host,
+						 conn->port));
 
 	timeout_remove(&conn->to_connect);
 
@@ -1503,7 +1506,7 @@ smtp_client_connection_connect_next_ip(struct smtp_client_connection *conn)
 	}
 
 	connection_init_client_ip_from(conn->client->conn_list, &conn->conn,
-				       NULL, ip, conn->port, my_ip);
+				       conn_name, ip, conn->port, my_ip);
 
 	smtp_client_connection_do_connect(conn);
 }