postfix forwarding mail with size less than
I would like to find a solution to the following problem: On my primary MX server, I have postfix installed with a bunch of local accounts that receive mail into maildirs. The mail server is also running Courier IMAP, and mail is read by our employees via Thunderbird. I have different redirections for different accounts in my alias file. I would like to forward, for one account, only the mail that is less than a given size. Imagine I would like to have a copy of my INBOX on gmail or yahoo, but don't want the e-mails with attachments or large in size. I would also like to forward all my e-mails to a secondary server in my network to test different spam filter configurations on the secondary server. Imagine I receive hundreds of e-mails with pretty large attachments, so my primary MX server would go on overtime forwarding the large mail to the secondary server. That's just what I am trying to avoid. Any suggestions?