[SunHELP] Email replication

[Shain Miley]

Hi,
Can anyone suggest a way in which I can get real time email replication 
to a second server?  Currently I have two external drives that hold the 
data and twice daily I use mirrordir to copy the data from the original 
to the backup drive, the problem here is that the backup data is 
anywhere between 0 and 12 hours old.  I could run mirrordir more often 
but what I want to do is have a separate server get a copy of any email 
so in the case of a server failure the other machine can be brought up 
as the original as seamless as possible....any ideas?
Thanks,
Shain