First, I suggest looking in File Explorer to verify that the inbox itself is that size, and not a combination of files. I mention this because sometimes users report a large size when, in fact, it is multiple temporary files from failed compactions. Normally, compacting the file works. If you exit TB and delete the inbox & inbox.msf, thunderbird will repopulate it on restart. No need to recreate the account.

Thanks for the tip. I couldn't compress, because of to less disk space remaining.

Meanwhile, my first approach to set the files local to a 180 days and deleting some bigger mails somehow did the job.

I have a HUGE Inbox (3402Mb) and yet the Inbox has just 25 messages plus 22Mb of attachments. So I followed David's suggestion to delete Inbox and Inbox.msf, placing them out of sight. Restarted TBird and the Inbox was EMPTY. I would have lost my files!! So I replaced them and all is well but the Inbox is still HUGH! How can I compress it, please? Bruce

So, on browsing around Support, I discovered that if I Right Click the Inbox, there is a COMPACT option. It reduced the file by 3.2Mb. Fantastic!! Now my backups will proceed MUCH faster!

Question to BruceWF: is that an IMAP or POP account? Deleting has always worked for IMAP.

Thanks David. As the folder is labelled hpop3@... I'm assuming it is a Pop account.

Bruce

That explains why removing the account didn't cause it to restore. POP accounts are resident on your PC, whereas IMAP accounts are resident on the server. That allows a user to delete the files on PC and they will repopulate. I'm glad you took the safe approach of backing up first.

Thanks for your help, David. Yes, I've been caught before on other deletions - once bitten twice shy!! I move the file elsewhere to test the effect. Anyhow, it worked, and the COMPACT option, which I'd never noticed or used before, was tremendously effective. Just what I wanted! Bruce