I installed a new ASA 5520 for a client that hosts websites over the weekend. The client has a POP3 server which their clients use to send emails out of the internet. One of the clients is having intermittent issues doing this from a scanner that sends the emails to the POP3 server. I looked at the log on the firewall and I am seeing:
Deny TCP (no connection) from 220.127.116.11/1065 to 18.104.22.168/110 flags ACK on interface outside.
I have not found anything on Cisco's site or google.com for this issue. I am out of ideas as of now. I thought it may be something with the default inspection policy-map, but that doesn't inspect POP3.
TIA for any ideas.