diff --git a/offlineimap/folder/IMAP.py b/offlineimap/folder/IMAP.py
index c405431..e0c0cc7 100644
--- a/offlineimap/folder/IMAP.py
+++ b/offlineimap/folder/IMAP.py
@@ -571,7 +571,7 @@ class IMAPFolder(BaseFolder):
 
                 #Do the APPEND
                 try:
-                    (typ, dat) = imapobj.append(fullname,
+                    (typ, dat) = imapobj.append(self.getfullname(),
                         imaputil.flagsmaildir2imap(flags), date, content)
                     # This should only catch 'NO' responses since append()
                     # will raise an exception for 'BAD' responses: