Can you redirect a ip address on an ASA 5500?

I have an issue, which I know what it is, do not know how to solve!!

On the inside interface and network, we have a server at, (as an example) 192.168.87.1, which acts as an email server.

The outside ip address of the ASA is, say, 200.0.0.1.

The ASA directs any imap requests from the outside interface to 192.168.87.1, which works fine from the outside. Users simply open up email, and collect emails etc.


Butt.. wwhen they come inside the office, their machine of course attempts to contact the ip address 200.0.0.1. the ASA knows it is outside interface, so they are unable to collect emails.

Any ideas as to how solve this issue, so that any internal IMAP requests from machines on the inside to 200.0.0.1 are directed to the machine inside on 192.168.87.1?