It seems that all of the sudden receiving emails to my domain with attachments from Google Apps\Gmail has become an issue. Emails without attachments come through without issue.
We internally host an Exchange server; Version: 14.02.0387.000.
Here is the message I receive - it takes at least a day if not more to receive this:
This is an automatically generated Delivery Status Notification
THIS IS A WARNING MESSAGE ONLY.
YOU DO NOT NEED TO RESEND YOUR MESSAGE.
Delivery to the following recipient has been delayed:
Message will be retried for 2 more day(s)
Technical details of temporary failure:
Missed upload deadline (899.98s) (state SENT_MESSAGE)
----- Original message -----
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed;
X-Received: by 10.28.129.131 with SMTP id c125mr9337825wmd.21.1447856547424;
Wed, 18 Nov 2015 06:22:27 -0800 (PST)
Received: by 10.28.72.70 with HTTP; Wed, 18 Nov 2015 06:22:27 -0800 (PST)
Date: Wed, 18 Nov 2015 09:22:27 -0500
Subject: Attachment test from gmail
From: Christina Taylor <email@example.com>
To: Christina Taylor <firstname.lastname@example.org>
Content-Type: multipart/mixed; boundary=001a114247f63450160524d15fa5
Other details that might help to diagnose; we have a WatchGuard firewall w\SMTP proxy and Trend Micro WFBA deployed.
Any help is greatly appreciated.