Lost mails in inbox and outbox

Can you explain why I lost the content of my emails from 04-06-2020 11:51 to 21-11-2020. It's only the content, I still have the subject of the mail. Also, the mails of the dates outside the specified area are normal. Is there anything that can prevent this, because I have lost several important e-mails.

Greetings,
Albert Keur
[email protected]
Version: 8.1.876

If you login to your email provider using their web interface, can you see the messages and their content?

When I receive an email, the content is present. The mails, the content of which has disappeared, are old mails from about six months ago. 

When receiving the mails, I have the webmail box at the provider automatically emptied, so there are no mails to be found.

Greetings,
Albert

OK, you are using POP3, so the messages are no longer on the server. The only option will be to restore from a previous backup.

The problem with POP3 is that all the messages are stored on your computer only, so if you just restore, you will lose all messages since the last backup. Here’s what to do:

  1. Disconnect your computer from the Internet and make a backup so the current messages will be safe. To do that go to Menu > Backup.

  2. Restore the last backup made after 21 November using Menu > File > Restore.

  3. Find the missing messages and export them by selecting them, then by right-click choosing Save As. This will save all the selected messages to your hard disk.

  4. Restore the backup you made in step 1, using Menu > File > Restore.

  5. Import the messages you saved in step 3 using Menu > File > Import > Email (eml).

  6. Reconnect your computer to the Internet.

Sorry, but you didn't ask. I am using: imap. 

I use the automatic backup and it is set to a frequency of 3 days (the last one was made today) and I keep the last 3.
I have all mails from January 1 up to and including the present in the inbox, including the missing ones mails.I have selected these missing mails and saved them in a subfolder of documents (eml). Because I had no backup to restore, I imported the missing mails from that subfolder to a separately created folder in eM Client. When I went to view that folder I saw all the mails indicated with: [email protected]

You said you have the server Inbox automatically emptied. That is not what happens with IMAP.

Are you maybe moving the messages from the Inbox to Local Folders?

I have moved several mail to local folders, but there is nothing to it. Only in the inbox and the outbox.

Sometimes reinstalling eM Client can help.

So try uninstall eM Client making sure NOT to delete the database directory when asked, then download and install the latest version again from the Release History.

See if there is any difference.