[Dovecot] Limit maximum connections for user/IP on proxy

Hi,

Is it possible to limit the maximum number of IMAP connections allowed for a user from each IP address, on the proxy server instead of on the mail store server?

mail_max_userip_connections works well when the client is connection to the mail store without proxy, but when using proxies the POP/IMAP server will register the remote IP (rip) as the proxy server's IP address - thus a low limit will be reached quite easily.

Thanks

-- Martin Abrahamsson