Exchange 2000 & MDaemon

Hi dear every body,
We have two mail servers, one exchange 2000 & other Mdaemon. The second is backup & just acts as a gateway which stores emails of the domain. We need exchange to connect to mdaemon periodically to download its stored mail & dispath them to their mailboxes.

How can we do this & is it possible to use ETRN to do so ?

Thank you in advance,
Mohammadi