diff -ur fetchmail-5.9.11/sink.c fetchmail-5.9.11.returnpath/sink.c
--- fetchmail-5.9.11/sink.c	Tue Dec 31 01:26:06 2002
+++ fetchmail-5.9.11.returnpath/sink.c	Tue Dec 31 01:25:32 2002
@@ -672,6 +672,9 @@
     }
     else if (strchr(msg->return_path,'@') || strchr(msg->return_path,'!'))
 	ap = msg->return_path;
+    /* in case Return-Path was "<>" we want to preserve that */
+    else if (strcmp(msg->return_path,"<>") == 0)
+	ap = msg->return_path;
     else		/* in case Return-Path existed but was local */
     {
 #ifdef HAVE_SNPRINTF
diff -ur fetchmail-5.9.11/transact.c fetchmail-5.9.11.returnpath/transact.c
--- fetchmail-5.9.11/transact.c	Tue Dec 31 01:26:06 2002
+++ fetchmail-5.9.11.returnpath/transact.c	Tue Dec 31 00:04:32 2002
@@ -665,6 +665,8 @@
 	 */
 	if (!strncasecmp("Return-Path:", line, 12) && (cp = nxtaddr(line)))
 	{
+	    if (cp[0]=='\0')	/* nxtaddr() strips the brackets... */
+		cp="<>";
 	    strncpy(msgblk.return_path, cp, sizeof(msgblk.return_path));
 	    msgblk.return_path[sizeof(msgblk.return_path)-1] = '\0';
 	    if (!ctl->mda) {