Exchange Receives But No Delivery

I'm not sure where this error came from seems like it just popped up...but don't they all.

Exchange has been set up to connect to our mail server using the POP3 Connection Manager. It has always connected, downloaded, and distributed everyone's email to the proper exchange account. Now all of a sudden it's getting the email from the mail server but it's not putting it in the exchange accounts...honestly...I don't know what it's doing. Sometimes a sender will receive a returned email saying

"
Delivery to the following recipients failed.

mspop3connector.<username>@<domain>.com
"

If anybody knows what's going on, or might have any kind of inkling, I'd really appreciate the help. I've been combing the net for solutions and have come up pretty empty handed.

I ended up reinstalling exchange which was easy and fixed the problem. I did find what looks like a viable solution though. I'll post for future queries.

It seems that the POP3 Connector adds mspop3connector to the beginning of each address when it obtains POP3 mail. The SMTP event sink is in charge of removing this temp address before delivery. To fix the event sink one just has to execute

\Program Files\Microsoft Windows Small Business Server\Networking\POP3\IMBREG.EXE

then restart the IIS services by running IISRESET from a command prompt.

I found multiple articles stating this is a viable solution. Good luck