The following recipient(s) could not be reached:
firstname.lastname@example.org on 6/23/2006 12:30 PM
There was a SMTP communication problem with the recipient's email server. Please contact your system administrator.
<exchange.that.local #5.5.0 smtp;550 Relaying is prohibited>
Sending from "that.com" to "this.com" is sending back this error. All sides have Exchange 2003 with SP2. We also have problems this "that2.com" sending to "this.com"
"this.com" can send to "that.com" and "that2.com"
I think it is something with IMF but I am just not sure. Wwe ("this.com") are getting email from all other people but a certain few domains....