- Plesk Onyx for Linux
The email reached the recipient mailbox which is full.
Why is the bounce message not sent to email sender?
The email stays in the mail queue on the recipient side (it can be seen on the Plesk > Tools & Settings > Mail Server Settings > Mail Queue page) during the mail queue lifetime. By default, Postfix, like most mail services, will keep trying to deliver mail for 5 days.
After the email leaves the mail queue the bounce message is sent to the email sender.
To check and modify the queue lifetime follow the steps from this article.