Trying to upload some backups after moving from one email platform to the other but they are not uploading.

More information may help. Was the backup created by the toos>export menu, or by other means? Can you do a screenshot of the backup from windows file explorer? You indicate that you first created an account on the new platform and then attempted to upload backup. Please clarify. thank you

Hi, To give the full context:

A backup was created by copying and pasting the Profile Folder.

The old mailbox was deleted and the new one was created on the new email server. When I tried to upload the backups, since the new email platform uses the same imap server as the old one, the email would synch with the current server and delete the old data.

So what I did is that I've launched the profile offline using the ImportExport NG tool and then backed up just the mailbox using the same addon.

Then, I've launched the email on the new server and uploaded the backup of the mailbox. But now, the emails are getting this error:

[Exception... "Component returned failure code: 0x80004005 (NS_ERROR_FAILURE) [nsIMsgMessageService.streamMessage]" nsresult: "0x80004005 (NS_ERROR_FAILURE)" location: "JS frame :: resource://mboximport/content/mboximport/modules/mboxImportExport.mjs?14.1.17Tue%20Apr%2007%202026%2017:16:53%20GMT+0300%20(Eastern%20European%20Summer%20Time) :: getRawMessage/< :: line 679" data: no]

Some folders seem to be empty as well.

When the backups were made, the person fogot to close Thunderbird so the data might have gotten corrupted. I've tried running the Repair function but it can't be run offline and if I go online, the email just synchs up with the new server.

If the original backup is still available, you may be able to salvage it. Try these steps:

1. remove the folders that have the errors
2. with the importexportool addon, do the following steps
3. highlight Local Folders
4. rightclick and select a desired message mbox to import and press enter key. (TIP: the messages are in pairs, such as inbox, inbox.msf, sent, sent.msf. IGNORE the msf entries.
5. repeat above step for each desired message folder
6. once done, verify the results. If the folders were from IMAP accounts, they may have been just headers, or headers with partial content. You can't fix that.
7. if you want to merge the retrieved messages into the parent account, then do this:
8. select one of the imported folders,
9. now, highlight the messages in that folder, rightclick and select COPY to the receiving folder. (DO NOT use MOVE.)