I tried deleting one of the accounts and recreating it, but the read messages still did not appear.

I've searched for other related questions, but couldn't find the same problem. If there is an answer on the site, please direct me to it.

The first thing to point out here and it is crucial, is that your settings in Thunderbird mean nothing if your IMAP server deleted the mail for any reason. That change will reflect to Thunderbird regardless of any local setting. That is fundamentally the whole point of IMAP, having multiple applications seeing exactly the same folders and data in those folders.

Thunderbird will honor it's settings and not initiate any deletions, but it will adhere top the server setting and delete via synchronization. So really the first thing to do is log into the relevant web mail and see if there is any mail there for Thunderbird to synchronize.

For example;

• You close an IMAP mail account and the address is deleted by the server, then the local copies will also be deleted. That is how IMAP works. It is actually rather useless as an archival platform.
• You delete most of the mail on your phone because it is complaining it is full. IMAP synchronizes those deletions to the mail server the mail server sends out the deletions to Thunderbird and Thunde4rbird undertakes it's deletions to match the canonical copy on the mail server
• You delete mail from the all mail folder in gmail and it disappears from everywhere. Both in Gmail and on IMAP connected devices as that it the only real copy of mail gmail holds.

If your mail still on the server?

Thank you for responding to my query!!

- Yes, I checked that all my email is still on the server before posting my question. - I only access my emails on my desktop. I do not have Thunderbird on any other devices. - Thunderbird is the only program I use for accessing email. No gmail or anything else. The only exception is that I accessed my email on the server's website AFTER seeing that the "sent" emails had disappeared.

Background: I have a year-old Mac with Ventura. Both the Mac and Thunderbird are set to update automatically. I have no security system other than the mac's own.

This is my first Mac and the first time I've had a problem with anything. I'm not computer savvy and especially not Mac savvy.. I looked at the articles "Disappearing mail" and "Empty folders" on Mozillazine and went through many of the steps without discovering the problem.

Since I haven't found a way to pull the "read" messages from the server into Thunderbird, I would like to uninstall Thunderbird and delete my profile EXCEPT for my address book (and, if it's not too difficult, my message filters) and then reinstall and set up my accounts anew. I don't use the calendar or chat functions. I was able to locate the profile folder with all the accounts and .msf files, but don't know how to open them. Ive been working my way slowly through the various articles and instructions, but if you can help me accomplish this reset, I'd appreciate it. I have never done anything with profiles before.