[CentOS] Load balancing email?

Tue Oct 25 22:03:55 UTC 2005
Benjamin Smith <lists at benjamindsmith.com>

Currently, we have two mail relays for inbound messages, and a third for POP. 

The inbound messages go thru all the CPU-intensive anti-spam stuff, and then 
they relay it to the POP server for pickup. 

Currently, one of these is the "primary", and the other is "secondary", and 
I'd like them to be considered more or less as equals, since the "primary" 
system is getting beaten pretty hard. 

The DNS zone file says something like this: 

###############################
@isp.com 
<SNIP>
                IN      MX      100 mx1.isp.com. 
                IN      MX      1100 mx2.isp.com.
<SNIP 
################################

I seem to recall that I make them act as "equals" by simply changing this to 

###############################
@isp.com 
<SNIP>
                IN      MX      100 mx1.isp.com. 
                IN      MX      100 mx2.isp.com.
<SNIP 
################################

so that they both get about the same amount of inbound messages. Has anybody 
here actually done this? How well does this work as far as failover if either 
system fails? 

-Ben 
-- 
"The best way to predict the future is to invent it."
- XEROX PARC slogan, circa 1978