Dovecot Proxy and Director

[Gandalf Corvotempesta]

Hi,
just a simple question: by using a directory and a proxy, I would be
able to totally hide the pop3/imap server ip addresses from outside?
I'm asking this because I would like to hide the real server IP for
security reasosn (DDoS and so on).

The proxy would be placed on servers with high bandwidth while the
pop3/imap dovecot servers are placed in a small datacenter that would
go down easily in case of attack