I have recently set up an exchange environment for a client. They are a small company with less than 50 user accounts. The server has been running fine for over two weeks, however users are now receiving incoming emails hours after they have been sent.
The configuration I have setup is mail comes in through an ASA5505 with Static NAT directing the traffic to a Barracuda 300 Spam and Virus filter. The Barracuda does it thing and then forwards the mail to the Exchange server. In the message log of the Barracuda it shows that the email has been received and "allowed", but it doesn't show up in the users mailbox for a long time.
Any ideas? Thank you.