diff --git a/imap-send.c b/imap-send.c
index c88d842819..1894a18f90 100644
--- a/imap-send.c
+++ b/imap-send.c
@@ -1082,7 +1082,7 @@ static void server_fill_credential(struct imap_server_conf *srvc, struct credent
 		return;
 
 	cred->protocol = xstrdup(srvc->use_ssl ? "imaps" : "imap");
-	cred->host = xstrdup(srvc->host);
+	cred->host = xstrfmt("%s:%d", srvc->host, srvc->port);
 
 	cred->username = xstrdup_or_null(srvc->user);
 	cred->password = xstrdup_or_null(srvc->pass);