Thunderbird Slow Running?

This was a tip that we just had to share with everyone. Our email tool of choice here at Silva Tech, is Mozilla Thunderbird with the “Ligtning” calendar plugin. Its worked very well with the multitude of Google Calendars/mail accounts that we maintain for clients, but recently the program started to crawl on a regular basis. Clicking between mail messages within a particular Gmail account would take a few seconds, and then mysteriously speed up later. Since our accounts are all running off of a shared storage device, we ruled out our local network and then our internet connection as the culprit. Coincidentally, the Gmail service itself was having some issues, so that didn’t help us narrow down the issue! The problem still existed, even while running thunderbird in “Safe Mode”.

The “a ha” moment came when we brought up Taskmanger (Win7) and started clicking through messages within our inbox. The delay was certainlty noticeable, but one process that ALSO spiked was the “MsMpEng.exe” process, belonging to the freely available Microsoft Security Essentials. We have NEVER had any issues with running Essentials, slowing down our programs, and in fact that is why we have recommended as the base level of protection on any workstation.

We went into MSE (Microsoft Security Essentials) and added an exclusion for our “thunderbird.exe” process. Immediately thereafter, Thunderbirdwas roaring again. We also noticed that our Calendar speed up drastically as well. For some reason with larger mail boxes, MSE was trying to scan every access of a single email message, which caused all of Thunderbird to slow for a few seconds. This just started happening, so I imagine it was part of our latest security updates. That is entirely a shame, because we had never any problems with the free software suite in the past.