So I know that has been partially answered here
Is there any better solution yet than opening each sqlite database, querying mails, and sending each mailid to gromox-mbop ?
I've checked rules, but AFAIK they only have fixed date rules, no "older than".
I have a mailbox that gets like 500 automatic mails a day, that I just don't want to keep after a couple of days, hence the question.