I am trying to find a way to determine if or why our Exchange server/spam filter is blocking desired email from UK regions. I cant do any header checks because I never receive any email into Outlook. I can request that they send the email to a pop3 account and it goes through fine. I researched the DNSstuff.com info and found everything to be legitimate about the domain in question. Please pass me some tips on how to trace emails or mainly just determine if it is my Exchange server blocking the addresses, or where else they might be stopping at. I can send and receive to that email address using a pop3 account. Can I have them run a trace on their email, which would tell them exactly where the email stopped at? Any help is appreciated.