Old mails repeatedly marked as unread

[JanG]

I encounter the same problem I started once to encounter in older versions.
Each day in the morning,  after my first sync aqua mail shows my old and already read e-mails as unread.  Those e-mails are constantly marked as read in my e-mail account opened through a www interface but even though I toggle them as read in aqua mail the next I have 6 new e-mails and these are those I have marked as read.  It started at some poont without any changes in aqua mail settings.
Do you have any clues how to fix it without having to delete these mails?

[Kostya Vasilyev]

Hello,

Sounds like it's a POP3 account where the mail server shuffles the order of messages (relative to their dates).

If you can use IMAP, please do (you'll have to add the account into AquaMail again, in Manual setup mode, as IMAP).

If not, please long press the account, choose Options and Folders / Account options and increase the "messages to keep" setting. Ideally, you'd want it to be larger than the total number of messages on the server, but values above 250 or 500 might be impractical.