I can send mail using horde fine, the recipient gets them, but when I try to SEND mail to an email used by horde/plesk I get the following error.
logs show the emails aren;t even reaching the mail server, they are being rejected on the way to the mailbox.Reporting-MTA: dns;bay0-omc1-s18.bay0.hotmail.com
Arrival-Date: Mon, 28 Apr 2008 08:07:48 -0700
Diagnostic-Code: smtp;550 <email@example.com>: invalid address
DNS and all that good stuff checks out. ideas?