How to mark messages as read on Yahoo-server?

I have a Yahoo-account. I read the emails that I receive on this account on both my laptop, using EMclient, and on my iPhone. Previously I used Outlook and Windows Live Mail to access my Yahoo-account and those programs would mark the downloaded message as read on the Yahoo-server. The result of this was that messages that I already downloaded on my computer would not appear as unread or ‘new’ on my iPhone. EMclient does not mark the messages as read, nor can I find a setting that would do that. It only says ‘leave a copy of the message on the server’, which is fine, as long as it marks the message as read. Can this be changed?

Hello Fred,
is your yahoo account set up as POP? Can you check the setting in Menu>Tools>Accounts?
If so, are there any error messages in ‘Menu>Tools>Operations’ when downloading mail ?

Regards,
Olivia

Thank you for your reply.

Yes, it is set up as a POP-account. And no, there are no errors listed