Email being blocked by AT&T with the following:
There was a SMTP communication problem with the recipient's email server. Please contact your system administrator.
<upjowers.com #5.5.0 smtp;550-22.214.171.124 blocked by ldap:ou=rblmx,dc=att,dc=net
Exchange 2003 - the SMTP Diagnostics from MXtoolbox shows "This server is not an open relay"
Just started on 6-12-2008 - BellSouth recently bought by A T & T hasn't happened for years - need to fix ASAP - How to get them (AT&T) to stop blocking my email