I have a customer that wants to send us email but cannot because we do not have a RDNS entry. First off Our Website is handled by one Company and our T1 line (ISP) is handled by another. The web site company has a MX record pointing to our T1 Line. My question is should I and if I should who should set up a RDNS for my MX record? I want to tell them to Kiss off because we can send and recieve mails from everyone else but them. They are blaming us and telling us to change. and all the “C’s” are saying yes lets do it becuase thier guy has a alphabet after his name. I need some info “ammo” for a conference call with this company later on. Thanking in advance for all insights.