Sorry, thanks, Bill...
Yes, I am talking about Zimbra Desktop.
Not sure which version. I've tried to find out, but am obviously doing something wrong.
My OS is Win 7 Home Premium.
This has only been happening for the last couple of months. Originally, it worked fine.
Not stalling on one particular message, it seems to be duplicating them all.
Using POP3, my ISP is O2.
I have just looked at my accounts, and next to the one that has issues it says:
"FAILURE COMMUNICATING WITH REMOTE SERVER. PLEASE TRY AGAIN LATER".
Hope this information helps?