I recently upgraded to ActiveForums 4.2.7 (I'm waiting on a help desk response so we can try upgrading to 4.3.5) and just figured out yesterday that it was the source of performance issues we've been having on our server lately. In the last week, it has made over 26 million POP3 connections to our email server. This is consuming 25% of the processing power of our 4 core server.

We've got 379 forums which all have MailConnector running, each with it's own mailbox. Prior to my changes yesterday (to make it run less frequently), each mailbox was making around 15,000 connections per day. Prior to the 4.2.7 upgrade, all the forums together were making 5000 connections per day.

Upgrading to DNN 5.6.1 did not help. There are no errors being thrown to the EventLog.

So what might be causing this? Will upgrading to 4.3.5 fix it?

The default setting is once every 2 minutes per forum. I have seen instances where the scheduler will run multiple times. This is usually caused when the scheduler interval isn't long enough to allow for all connections to be processed. Another option is to disable the scheduler task and setup a remote task to /mc/getemail.aspx. That will serve the same purpose as the scheduled task but offer more control for the process.

Will, there's something far more screwy going on. Each mailbox was making 15,000 connections per day, that's 10 connections per minute.

I've been decreasing the frequency the schedule task runs since yesterday. It's currently set to run every 4 hours. It's making things a little better but it's doing a huge number of connections (3600 per mailbox today) when it does run and working my very powerful 4 core machine very hard for 40 minutes most of the time it runs. And there's very little mail in any of these folders.

This definitely sounds like the scheduler issue we see from time to time. Keep in mind, Active Forums doesn't initiate the connection. Everything is based upon the scheduler. I believe I have a powershell script that you can add to your windows tasks that call the process for you. This is much more reliable in large configurations.

Thanks Will, I'm doing some testing now to make sure email is getting picked up properly using /mc/getemail.aspx

Posted By Will Morgenweck on 15 Mar 2011 02:59 PM
 Another option is to disable the scheduler task and setup a remote task to /mc/getemail.aspx.

How is this done?

I've setup my external monitoring service (I use BinaryCanary.com but there are thousands of others) to ping the /DesktopModules/ActiveForums/mc/getemail.aspx page of the site. It looks like this should work well but I'll be keeping a close eye on it over the next couple days.

I just noticed that DNN 5.6.2 (released today) "Fixed race condition in the core scheduler ". Wonder if that's related.

More than likely it is related. We haven't changed the mail connector in quite a long time. Based upon the volume you described, I still believe using the external service is a better solution.