I recently had to modify the IMAP server for about 5 mail accounts in Thunderbird and after doing so, for each account I only see new messages that arrived to the new mail server.
To make it more clear, I had 5 accounts like this: firstname.lastname@example.org, email@example.com, ..., configured with oldmailserver.com on port 993 and for all of them I changed the incoming mail server to newmailserver.com (yet on port 993).
After doing so, I no longer see all messages that I had received with oldmailserver.com.
Now, I am sure that Thunderbird did not delete the messages physically because my
c:\users\username\AppData\Roaming\Thunderbird\Profiles\rd4y3dca.default folder is still 15Gb big. Specifically, in the ImapMail folder inside of it, I have many subfolders named like this: mail.mydomain.com, mail.mydomain-1.com, mail.mydomain-2.com, mail.mydomain-3.com with the highest numbered one being the only to have a last modified date of today (and the second most recent one having a last modified date of about 6 months ago). Inside that most recent folder, I have one 1.5Gb INBOX file and an INBOX.sbd folder, containing other quite big files named "sent", "draft", "trash" (all the typical email account folders).
How can I proceed to restore for each account the old messages, so that they display together with the messaged received with the new server?
I am not sure what all those folders are and how I can proceed to keep the new server configuratio