So I have some external people that are unable to send mail to us. They get a bounce message back saying the messages timed out. In my logs, I can see the connection coming in: I see their EHLO with a 250 success message back I see their MAIL FROM command with a 250 success I see their RCPT TO: command with a 250 sucess message back Then... nothing.. the DATA command never comes through.. wondering if anyone has seen this or know why this might occur. Running Exchange 2003 SP2, IMF installed sitting behind an ISA 2000 server w/Server Publishing rules. This does not occur with everyone, just certain senders domains.