I am not receiving email from certain domains. e.g, @san.rr, @cox.net, @gmail.com, etc... but internal email is fine as with most other domains.
i have checked every where i can think of and i am coming up with nothing.
- dns/mx records are good
- ip is not listed on any black lists
- firewall / nat is configured correctly
- filtering software is not catching it / quarantining it
- traffic is normal / doesn't look like we are an open relay
i am running exchange 2003, trendmicro scan mail for exchange all sitting behind a cisco asa 5510