How long ago did you last use the XP machine? Is one of the accounts POP or is there just the single IMAP account?

David thanks for the reply.

I am still using the XP machine as my main PC, and in process of transferring stuff to the new PC... so I can stop using it.

I have 14 email accounts there, all are IMAP. Plus Local folders...

I did wonder whether because using XP the latest version I can use is old - v52, and the version I am trying to install it on is much later... If all else fails I might try installing v52 on the new PC then do the upgrades from there .

Also wondered whether being a 64-bit version causes any glitches...

The Thunderbird folder I am copying is 21.7GB but after restarting TB that goes down to 15GB. I can see that some files are being deleted by TB. Those files are in the ImapMail subfolder.

Okay, just a guess: check to see the settings on the accounts. There may be settings to delete messages over x number of days.

I don't think so, the mail appears then doesnt display when I restart TB. Plus there is mail going back years I've never seen any setting that auto deletes messages, apart from the Trash...

think I'll have to try reinstalling the same version on the new PC then if that works I'll upgrade versions via the check for updates option

thanks

You missed V68, where password storage was upgraded so your password files will be corrupt.

Open the profile folder and delete key3.db, key4.db,pkcs11.txt, logins.jsonand any signons files. Not all files will be present, just delete what you have.

Hi Matt, yes I think you are right.... last night I decided to load v52 on the new PC and the mail was OK at that point, so I went through a number of suggested updates including v68. So now am on the latest version and the mail is all showing up correctly, all my filters etc have come across well.

Thank you