Email marked as read in other email clients

[Enju]

Hi,
Until now employees have used Thunderbird, RoundCube and Gmail application (on the phone) as an email client. If the user has marked a email as "read" in one client, it has also been marked as read in the other client.
Problem: After configuring the email address in EspoCRM, other clients (Thunderbird, GmailApp, RoundCube) began to freak out - messages in the above clients are automatically marked as read although they have not been marked as read in any client.
Thank you for help.

[Maximus]

Hello,
please check the 'Keep Fetched Emails Unread' box in your IMAP settings.