We are planning to put two Ironport devices load balanced through Cisco CSS devices. The objective is to monitor the mail queue size on the ironport devices as a criteria for load balancer to forward the mails.
If the queu size on any of the Ironport device reaches value "x" then CSS should mark that Ironport as down and forward no more messages till the time queue size doesn't come below "x".
Appreciate any suggestions.
There are multiple solutions, but it always involve scripting.
First, you need to be able to provide the queue size to the external world either through a special protocol, or http, or snmp, ...
Then you need to build a script on the CSS which will collect the queue size using the proper protocol and extract the queue size from the server response.
You can then use this script as a probe to mark if the server is available or not.