[Dovecot] Using dovecot in performance tests?

Hello, please Cc me into replies, I'm not subscribed. My job as of late involves testing the performance of software that functions as IMAP/POP proxy. I have an account set up where a known collection of emails is delivered from postfix, and is then dowloaded by MUA on the test machine. The thing is, sending the emails (from a separate machine on LAN) actually takes more time than the download by MUA and is (probably?) an unnecessary load on the system that I could avoid. Ideally, I would like dovecot to treat all messages in a user's mail store as always-new, ie. they would be downloaded whenever the user connected (MUA settings and state permitting). Is something like that possible?

Michal Zatloukal