In my latest SecurityWeek column, “When to Deploy a Load Balancer for Email,” I discuss a common load balancer configuration, as well as where to deploy a load balancer. I’ve also highlighted some of the best practices for deploying them in the email infrastructure that include:
- Deploy a load balancer for mail submission agents that accept email messages from internal email clients
- Deploy a load balancer for MTA infrastructures used by high volume email generating applications
- On the inbound Internet gateway, use multiple MX records to do the load balancing
With these recommendations, I hope to help you leverage the technologies for their appropriate uses—Service levels should be maximized while providing the most robust configuration to handle outages.
Be sure to check out the full article here, and as always, we look forward to your comments below.
Greg, I would add one point to your option (3) where Load Balancers make sense: if your traffic is high enough to require a high number of inbound servers, the use of load balancers (with several VIPs) would allow reducing the size of the MX records, i.e. you probably don’t want 100 hosts in your MX record.