Periodically I get the above help message and there are some simple things you can do straight away.

1. Is your web space full?
You can login to the control panel to check that. You should see that you still have space available, or it will let you know if it’s full - usually there is a warning message generated but if your mail box has filled quickly, you might not get it.  If you find that your webspace is getting full quickly, you may need to upgrade your webhosting service to a bigger web space.

2. Is there email blocked in the mail server?
Perhaps someone sent you a huge file that can’t download. If that’s the case, view the offending email and print it off, if necessary, then delete it from your mailbox in your control panel. After that everything should start to download again. You may get repeated messages - that’s normal because the server kept trying to deliver repeatedly and would start all over again till it got to the spot where it was stuck.

3. Have you tried shutting down your computer and starting back up again?
It might just be a temporary problem and rebooting your computer may clear the error.

4. Is there anything else I should know?
Have you recently had something change on your computer, or even changed ISPs?  We may need to do some testing to see what else could be causing it.