diff --git a/SoObjects/Mailer/SOGoMailAccount.m b/SoObjects/Mailer/SOGoMailAccount.m
index 1b2711139..7b3b426c3 100644
--- a/SoObjects/Mailer/SOGoMailAccount.m
+++ b/SoObjects/Mailer/SOGoMailAccount.m
@@ -787,7 +787,7 @@ static NSString *inboxFolderName = @"INBOX";
       else
         guid = [[[result objectForKey: @"status"] objectForKey: currentFolder] objectForKey: @"x-guid"];
       
-      if (!guid)
+      if (!guid || [guid isNull])
         {
           // Don't generate a GUID for "Other users" and "Shared" namespace folders - user foldername instead
           if ((otherUsersFolderName && [currentFolder isEqualToString: otherUsersFolderName]) ||