I have a SMTP relay that is used to accept all email on behalf of my company. I have the same domains listed as acceptable inbound remote domains, as the list on the routing tab of my exchange server. I can accept nearly all of the inbound email for all these domains, however, some email with very similar domain names is not being accepted by the exchange server when the SMTP IIS5 relay sends it. example CONWAYDATA.COM comes in fine. CONWAYDATA.NET does not. (it sits in the queue at the SMTP IIs5 server waiting to be accepted by exchange.) Here is the eventlog data from the SMTP server. ========================================== Event Type: Warning Event Source: smtpsvc Event Category: None Event ID: 4000 Date: 1/9/2003 Time: 11:58:39 AM User: N/A Computer: MAILGUARD Description: Message delivery to the remote domain 'conwaydata.net' failed for the following reason: The remote server did not respond to a connection attempt. Data: 0000: d2 02 04 c0 Ò..À =========================================== Both internal and external DNS entries are all identical for each of the .NET/ORG/COM versions of this domain, the others arrive, yet this one does not. What the Heck is going on?!