Prevent domain from being blocked

[alsmith]

I searched but not sure I'm searching for the proper thing. I have one customer that has more than 30 users using email. They constantly are kicking off the firewall and I have to reset it.
Is there a way to restrict the firewall from blocking people using one domain on the server?
I understand this could cause trouble.

[sawbuck]

Only by IP or CIDR not by domain.

[Smjork]

Put the specific domain in your csf.dyndns file, it might just do the trick
Also make sure you read the comments in that file before adding the domain :-)