How common is this scenario? It's such a pain in the ass and I'm getting sick of dealing with it..... OrgA emails OrgB. Email goes through MailHostingCompany's SMTP server. OrgB rejects OrgA email because SPF disallows HosterA's smtp server from sending email on behalf of OrgA. In the headers below, 210.48.108.215 appears to be an SMTP server at grunge.hosts.net.nz =================================================== This message was created automatically by mail delivery software. A message that you sent could not be delivered to one or more of its recipients. This is a permanent error. The following address(es) failed: admin(a)safegas.co.nz SMTP error from remote mail server after RCPT TO:<admin(a)safegas.co.nz>: host mail.safegas.co.nz [210.48.108.77]: 550 SPF: 210.48.108.215 is not allowed to send mail from oasystems.co.nz ------ This is a copy of the message, including all the headers. ------ Return-path: <user(a)oasystems.co.nz> Received: from witch.oasystems.co.nz ([202.180.74.56]) by gunge.hosts.net.nz with esmtp (Exim 4.69) (envelope-from <user(a)oasystems.co.nz>) id 1ObmQC-00011s-0M for admin(a)safegas.co.nz; Thu, 22 Jul 2010 15:26:09 +1200 =================================================== -- Regan