I've got a weird problem with out SBS 2011/Exchange 2010 system. For the last few days, a handful of emails for seeming random users are either being delayed by over an hour or are not getting through at all. There's been no changes to the server other than updates.
There's nothing in the event logs to suggest a problem. The headers of the delayed messages look like this..
Received: from st11p00mm-asmtp003.mac.com (188.8.131.52) by office.mycompany.org.uk
(192.168.1.2) with Microsoft SMTP Server id 14.1.438.0; Sat, 1 Feb 2014
Received: from [192.168.1.64]
(hostxx-xxx-xxx-xxx.range86-157.btcentralplus.com [86.157.xxx.xxx]) by
st11p00mm-asmtp003.mac.com (Oracle Communications Messaging Server
7u4-27.08(184.108.40.206.7) 64bit (built Aug 22 2013)) with ESMTPSA id
<0N0B00JIOMXZD620@st11p00mm-asmtp003.mac.com> for firstname.lastname@example.org; Sat, 01
Feb 2014 14:30:05 +0000 (GMT)
X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 spamscore=0
suspectscore=0 phishscore=0 adultscore=0 bulkscore=0 classifier=spam adjust=0
reason=mlx scancount=1 engine=7.0.1-1308280000 definitions=main-1402010070
Date: Sat, 1 Feb 2014 14:29:58 +0000
Subject: You're going to hate me but ...
To: Alan<email@example.com>, Simon
CC: Vick<firstname.lastname@example.org>, RICHARD
Sarah<email@example.com>, David<firstname.lastname@example.org>, Tim<email@example.com>, Mick<firstname.lastname@example.org>
Thread-topic: You're going to hate me but ...
Content-Type: multipart/alternative; boundary="B_3474109804_1209807"
X-CTCH-Error: Unable to connect local ctasd
Received-SPF: Pass (SBS-Server.mycompany-net.local: domain of
email@example.com designates 220.127.116.11 as permitted sender)
We have a Cyberoam CR25ia as firewall/AV/AS. Nothing in those logs suggest much either (although I'm not entirely sure if I'm looking the right place there).
Various tests and monitoring suggests that things are running fairly well other than the odd warning about lack of RAM. We've got 8GB RAM for about 8 concurrent users. CPU is trundling at about 8% load. 156GB free on system Drive. Server is mostly just for email with light fileserver duties. No other SQL servers or other heavy load stuff on it.
Not sure where to go from here. Any ideas?