why are messages deleted from inbox after I compact folders

Sometimes the emails were already deleted but for some unknown reason still showing. Sometimes scanning by AV products can cause some corruption, but there maybe other reasons like not compacting on a more frequent basis. But if the Inbox had become corrupted then Thunderbird may not be able to read which emails were marked as deleted, hence losing good emails. It really sounds like your Inbox mbox file may have become corrupted.

• Move all wanted emails out of the Inbox into other suitable folders for organising and storage.
• Delete any emails you do not want.

When Inbox is empty...

• Right click on Inbox and select 'Compact'

This should setup a fresh new Inbox mbox file.

It is generally advisable not to store emails in the Inbox. Use the Inbox for incoming emails that need to be read or sorted, limiting the number in that folder. http://kb.mozillazine.org/Keep_it_working_%28Thunderbird%29

Compact on a frequent basis. I will delete emails and compact the Inbox each day.

If you have an Imap mail account, you can set it up to expunge the Inbox on exit. This is setup in Account Settings > 'Server Settings' for the imap mail account.

If you have automatic Compact setup which runs when you can save XXMB, then suggest you lower the thresh hold to force more frequent compacting.

Toad-Hall said

It really sounds like your Inbox mbox file may have become corrupted.

• Move all wanted emails out of the Inbox into other suitable folders for organising and storage.
• Delete any emails you do not want.

When Inbox is empty...

• Right click on Inbox and select 'Compact'

This should setup a fresh new Inbox mbox file.

If 'Compact' doesn't set up a new, uncorrupted mbox file, you may have to delete the mbox and msf files for the Inbox from the profile folder, and have TB automatically create a new mbox when it's restarted.

http://kb.mozillazine.org/Compacting_folders#Real_fix

none of those suggestions solved my problem but I did the "compact" on my inbox. I do not receive many e mails, maybe 5 a day. would rolling back to an earlier version solve this problem?

Rolling back seldom helps, since most problems are in the separate, profile folder, not the program files folder. If you have an antivirus scanning email, disable that option, or run in Windows safe mode to see if it makes any difference.

I have not compacted any folders lately. This morning all my e mails were intact. After a few hours I put this computer in sleep mode After I woke my computer from sleep mode 3 hours later and logged into TB I clicked on the inbasket and my messages appeared for a second and disappeared. This happened for each channel except for trash.

I have Kaspersky but this also happened when I had Webroot anti virus.

This does not happen every day.

I don't think Webroot scans emails, but I suspect Kaspersky does (reason for testing in Windows safe mode). You can read about why email scanning should be disabled here:

http://kb.mozillazine.org/Antivirus_software

good article I have turned off scanning of my e mails hope this solves the problem ty