Cannot open INBOX anymore

Hi guys. I have bunch of IMAP accounts to which I can not connect to. I migrated domain to a new server, already recreated all accounts on a new server. Already moved a lot of messages from old INBOX to a new ones. All worked perfectly.

Then week later I realized some of the new accounts are still missing some messages from the SENT folders from my previous accounts.

I said to myself, OK no problem I will ctrl+a from SENT folder in old accounts and move them to new SENT folder. Just like I did before.

However for the love of god, I can not realize why my old Thunderbird accounts (which can’t connect to the old server anymore) does not want to roll out and open INBOX anymore. I only see INBOX and that’s it’ I can not browse them.

That worked but since I moved on, and since my previous webhosting shut down my previous subscription these old accounts can not connect to their old server. Which is expected. However files(emails) are still on my HDD.

When I browse files on my HDD I can see that all content is actually there in my profile folders. There are SENT files which are several GB in size so all data is still there.

Is there a way for me to extract those data from old IMAP accounts?

I tried offline mode but that’s not working.

Any tip will be greatly appreciated.