Just in case anyone searches for this - it has to do with
Thunderbird 2.0x
Slow deletes on email, slow moving from email to email.
Everyone tells you to compact folders, which is a good idea, but doesn’t clear up the problem.
After long bouts of trying to exclude profile paths, etc etc etc… I found the problem.
Switch your “On Access Protection Control” from “High” to “Normal”, and it will stop.
The second I switched the on-access protection back to Normal and re-launched Thunderbird, the slowness disappeared.
7/23/2007 - despite my best wishes, this thread has continued down the path of “compact folders”. All I can say is, that’s great, but it never came close to solving my problem. I hope this might help someone who had my specific problem, which was On-Access control set to HIGH, and Thunderbird slowness and deletion of email slowness. I had already tried all the other answers, including compacting folders.
Thanks everyone!
You make one valid point and then another that is debatable.
The comment about the level of the Standard Shield is quite right. avast scans the mail folders of Thunderbird on the high setting but does not on the normal setting.
The scanning overhead will therefore depend on the sizes of the files being scanned. On my system if I move a message from the Inbox (which I keep pretty empty) to a folder that is just over 100Mb in size then on the high setting there is a small but detectable pause as avast scans the 100Mb file (2-3 seconds). The pause is not there with the setting on the normal level.
As you probably know, no messages are ever physically deleted from a Thunderbird folder until the folder is compacted. Over time this can lead to folders becoming huge and containing large amounts of space occupied by messages that are marked as deleted. If you have the high setting and do not compact then you make the scanning delay considerably worse than it would be. The Thunderbird index files ( .msf files - which are scanned) are also unnecessarily larger for uncompacted folders too. So regular compacting helps (even on the normal level). Once a file is compacted then that is as small as it is going to get and the high setting will affect Thunderbird performance on large folders.
Just one other and perhaps more important point. avast does not really have a clue how to handle Thunderbird mail folders and is almost incapable of detecting viruses within them so there is just about zero value in having them scanned anyway.
The real email smarts in avast are in the Internet Mail provider. The best defense is to use that to prevent viruses ever getting into the Thunderbird mail folders in the first place.
I use the Xpunge extension with Thunderbird - it does a pretty good job of emptying the trash files and keeping my folders compacted.
I appreciate the feedback, but please realize you just talked about compacting, and as I mentioned in my post - that is the most common (and yet not solving the problem) item I got.
I already have the Auto Compact Folders set to 200k, which seems reasonable.
I have just read Alan’s post and if I read it right he isn’t saying that compacting will cure the problem completely if you have very large folders but reduce it to the minimum.
I don’t use Thunderbird, but OE, which doesn’t seem to suffer this problem, as we don’t see related posts about it.
I still regularly compact my folders, but more importantly I keep my inbox as small as possible (currently 7 emails in it) but I have a lot of Folders and sub-folders 114 in all so no single folder or sub-folder (.dbx file) gets really large. If one does get large I move some of the files into an archive of the same folder so I have current (this year) and archive for previous years. For me this keeps it manageable and easy to find emails.