Did you try compact your email? or repair your folder?

• In the Menu bar(Press F10 or Alt to unhide) go to File >> Compact folders
• Right click on the folder select Properties >> Rapair folder

Did you try create a new profile?

• New profile

Do you have an anti-virus program such as McAfee set to scan mail folders? If so, disable that function and see if performance improves.

I've downloaded the link for profiles, but nothing will come up. Can't get to site to add a new profile. Any ideas? tried compacting the folder, disabling McAfee, no help

OK so I figured out I needed to create a profile in Mozilla not Thunderbird (I guess, as I cannot figure out how to find profiles within TB) How does that help me in Thunderbird? How do I copy all email folders so I can try a re-install on TB? What about Thunderfix? I don't want to "fix" until I've got all my e-mails saved. Thanks

If the problem is mainly when deleting messages, and you have already disabled McAfee from acting on mail folders, try this first before setting up a new profile: select Help/Troubleshooting Information, click Show Folder to open the profile folder, exit TB, open the Mail (for POP accounts) or ImapMail (for IMAP accounts) folders, then the subfolders that are named for each account. In those subfolders, delete the Trash and Trash.msf files, then restart TB and see if you still have problems deleting messages.

So I tried all the fixes and nothing helped at all. I finally realized that onoly my inbox was affected, so I went thru tediously and deleted all e-mail that I didn't need (FWIW-sort them by name, then delete en masse). Got down to about 1200 or so, then moved all of them into a new folder I called inbox1. Now when new mail comes in I can delete it immediately with out having to wait. So far it's working-we'll see.

Your problem is almost certainly related to McAfee. And it probably is just a matter of time it comes back. Check this article.

https://wiki.mozilla.org/Thunderbird:Testing:Antivirus_Related_Performance_Issues#McAfee

I can't find any of those areas is McAfee. Maybe they were in the McAfee Security Plus program I deleted

I don't think anyone here uses McAfee. So better ask in a McAfee forum.

I will do that. In the mean time, I went into my sent folder that had 3900+ emails in it and it also was very slow, none of my other folders is slow. I deleted all the irrelevant emails from the sent folder, and it now works fine. Could this be a memory issue?

If it recurs, I'll remove MCAfee and install Nod32. Thanks

FWIW- everything worked well for a while, the pfffst!. OK, Uninstalled MA and installed a trial nod 32. No issues so far.