Found thefollowing messageonour Exchange 2007 server logs for a user'soutbound reply to an outside email . We host our own email. Any thoughts on how to resolve this? 550 5.7.1 <emailaddress.com>... H:MXB[our outside IP address]Connection refused due to abuse. Please contact your E-mail provider. Thx. KW

Your external IP address is probably on a block list of some sort. Check with your ISP to see if they gave you an IP address range that might be listed as a DHCP address somewhere. Also, check out on DNS Stuff, there is a test for checking to see if you are on an RBL.