We are sending quite large amount of email messages to our customers every month with Postfix. Big percentage of them have their email hosted with @example.com. But every month we are struggling to deliver all the messages because of greylisting.
Example.com provided us with specific settings for every 5 minutes window to stay out of greylist:
Max. cumulative limits for every 5 minutes to domain example.com
- 300 connections
- 100 000 messages
- total size of 180 MB
We are definitely not sending 100K messages so number of connections over this 5 minutes window seems to be the main issue. Could anyone help with specific Postfix settings to meet the criteria above only for connections to example.com?