With IMAP Thunderbird can only display messages which exist on the server. If you used a POP account previously, the old profile should still exist on disk, and the computer Company should be able to recover the existing local messages.

Thank You Christ1 for Your reply, They managed to recover mails, but it was only the headings. when I checked in offline mode, the e-mails didnt show, and when connected, they disappeared. I checked the files that they extracted, but there is no size big enouhgt on the files to be containing all emails.. Just spendt 2000 dollars on trying to fix and new LT, so... I`ll have to try to download Ubuntu or similar and try to access old computer trough cd rom if it is possible.

You'd need to confirm what's been the account type on the HP Laptop. If it's been IMAP, then it sounds like you did not enable synchronization, i.e. what's been on your disk where the headers only. There isn't enough information to determine why any headers disappeared when connecting to the server with the new installation.

It might been POP3, earlier, but I am not sure, but even so, The mails should have been on the chrashed HP laptop. Frustrating.. I`ll try to chech with my internet provider, and see if there is any backlog there... Thamk You again Christ1 !