SMTP Load Balancing

Is this for a single connection? Or multiple connections?

 

 

Most SMTP servers will connect once (Or up to about 4 connections, more is anti-social) and stream multiple emails across the single connection. one after the other in a pipeline. That's never going to be balanced as the balancing is done per connection. not per message.

 

 

if you are getting multiple connections and it's still not going to more than one node, I'd check your settings. What algorithm are you using to balance? RR might be your best bet here possibly. But I suspect you're being hit by the email pipelining... (Note that although you could disable it, that'll increase the processing overhead. Especially if your servers are doing any sort of anti-spam based on the inbound host).

 

 

H