Why are all emails being marked as read?

Question

Outlook

Why since some time ago (about a week) all the letters that came to outlook began to be marked as read by themselves? The mail service on the mail.ru resources has its own domain. Configured according to the typical imap protocol. From what I managed to google, nothing helped. Neither changing the password, nor deleting the entire outlook configuration. Even turning it off in the outlook settings so that it marks "Read" according to the rules. Moreover, there is no such thing in the web muzzle of the mail, everything is there as it was unread and remains until you read it with your hands or mark it as read. They become read already in the client. I would like to understand the reason for this behavior.

Answer 1

Most likely, this means that one of the clients is configured to use POP3 and not IMAP, when receiving letters via POP3 they are all marked as read. You can see the action log in https://e.mail.ru/settings/actions

Answer 2

decompose
check with another client
take the next step