Exchange 2013 SMTP Throttling
Posted on 2014-08-06
I am in the process of migrating to Exchange 2013 SP1 from 2010 SP3. In my environment, I have several .NET applications that authenticate to Exchange as an internal Exchange user and attempt to relay large amounts (1000+) messages through one of my receive connectors. Most of these messages are bound for internal users, but there are a few that traverse my outbound send connector. In Exchange 2010, this setup worked flawlessly. As soon as I redirect my applications to the new Exchange 2013 server, I start getting the behavior described below.
UG Application notifications sent to intended recipients at 8/6/2014 1:00:17 AM
AU-ABC or BAS/BCM Application notifications sent to intended recipients at 8/6/2014 1:00:18 AM
Grad Application notifications sent to intended recipients at 8/6/2014 1:00:20 AM
ERROR: firstname.lastname@example.org SmtpException: Service not available, closing transmission channel. The server response was: 4.4.2 Message submission rate for this client has exceeded the configured limit…
And then the last line begins repeating for multiple email addresses.
So, my first thought was that this must be a symptom of either the anti-spam or anti-malware transport agents, as I have both of these installed in my environment. I have disabled both agents and am still experiencing the problem. I am now thinking that this is a result of some kind of change in the throttling behavior of the transport service. I would like some other opinions before I start to dismantle my transport service. I also discovered that the "Get-TransportService" cmdlet has no equivalent in 2010. Any ideas on how to get this working?