[Dovecot] Where are flags stored?

Hello,

I don't now wheather this is IMAP or actually dovecot-specific, but I hope you people here knows about this at least: Where are flags like seen/unseen or e.g. message-priority stored?

My goal is to mark spam or other filtered by procmail as "seen", so that dovecot doesn't notify MUAs about new mail in IDLE mode.

Are there any mail-headers, so I can set these with procmail to accomplish that?

Thanks for help,

A