- Plesk 12.5 for Linux
Creating subscription takes 3-5 minutes due to long time to restart Postfix service.
Tools & Settings > Mail Server Settings > Outgoing mail mode set to Send from domain IP addresses and use domain names in SMTP greeting
There is a significant number of subscriptions on the server.
This is Plesk internal issue with ID #PPPM-4307 , which is planned to be fixed in future product updates.
Switch to either of the following Outgoing mail mode options:
Send from domain IP addresses - this should reduce amount of Postfix transports to the number of IP addresses. Postfix restart time will drop at least 10 times with this setting;
Send from the specified IP addresses - no additional transports will be configured at all, keeping postconf execution time (as well as Postfix restart time) to a minimum.