I have emclient on 2 computers.
One is set up as an imap account, the other as pop3.
Unfortunately I had made a misconfiguration in the emclient of the imap computer, I had activated that it should download the mails so that the search function can be used.
Now these downloaded mails no longer appear in the pop3 server.
However, they are still available at my mail provider.
How can I resynchronize the pop3 server so that it downloads all mails without deleting and recreating the pop3 account?
That just caches the messages, it doesn’t remove them from the server.
Unfortunately you can’t use POP3 reliably with multiple devices. When one device retrieves the messages, it either deletes them from the server or marks them as downloaded, so they won’t be available for the other devices. If you are using more than one device connecting to the same account, use IMAP. That way the messages are stored on the server and each device accesses them similar to webmail. If you read a message on one device, it is also marked as read on the others. If you send a message on one device, it is also visible in the Sent folder on the other devices.