I have a client who has advised they are receiving bounce backs when sending to certain addresses. Below is a copy of one of the bounce backs and from what I can see the issue appears to be related to SPF. I have checked their SPF record on MXToolbox and everything looks fine.
Your thoughts would be appreciated...
cluster3.eu.messagelabs.com #<cluster3.eu.messagelabs.com #5.1.3 SMTP; 553-SPF (Sender Policy Framework) domain authentication> #SMTP#
Original message headers:
Received: from mail.**.uk (EHLO mail.**.uk)
([220.127.116.11]) by c2beaomr06.btconnect.com with ESMTP id VDE42089; Fri, 20
Feb 2015 08:52:47 +0000 (GMT)
Received: from .local ([fe80::6d4f:de3c:296:5a56]) by
**-.**.local ([fe80::6d4f:de3c:296:5a56%12]) with mapi id
14.03.0224.002; Fri, 20 Feb 2015 08:52:46 +0000
Subject: Credit Card Application
Date: Fri, 20 Feb 2015 08:52:45 +0000
X-WatchGuard-Spam-Score: 0, clean; 0, no virus