Been learning Postfix and trying to setup my own mail queue server for newsletters (no mailchimp or sendgrid).
I'm stuck on the last thing I wanted to implement, which is delays/queue. I found a tutorial on how to rate limit here : http://steam.io/2013/04/01/postfix-rate-limiting/
However, they rate limit per domain, is it possible to rate limit by MX record ? That way if I try to send to user@gmail.com and user@domainmxatgmail.com it would be rate limited because they use same MX records?
I'm using virtual aliases & mysql. After I figure this out, my next step would be to figure out how to apply the policy to a specific sender from my server (e.g. newsletter@domain.com to be rate limited.)
I have rabbitmq installed on the server as well if that needed to be used, but as I understand, this should be the MTA's job.
Michael here says it can't be done.
Postfix - rate limit outgoing concurrent connections to one machine/ip
