Real Server Monitoring

[Jason Steenblik <jsteenbl@xxxxxxxxxx>]

I am running ipvs 0.8 on a 2.4.3 kernel and need to monitor the
availability of my smtp realservers.  What is the best method of doing
this?  

From my reading and short testing this is what I found (I think).

Mon worked but didn't seem as elegant as the others.
ldirectord doesn't work for smtp realserver.
Keepalived doesn't work with 2.4 kernels.

Are the above statements true or false?  Does anyone have any advice
about what to use to monitor the smtp boxes?

Thank You,
Jason