After some digging we managed to find out that Plesk restricts the number of IMAP servers and connections per IP address to pretty low numbers. To increase the values you need to change the following:

Find the file: /etc/courier-imap/imapd

Use SSH and then VI to open and edit the file: vi /etc/courier-imap/imapd

Change the following values: MAXDAEMONS=40   to   MAXDAEMONS=80

Also change the following: MAXPERIP=4  to  MAXPERIP=40

To save your file press Esc, then ZZ (in capitals), this shouldp ut your file to sleep and save the data.

Finally, restart courier-imap using: service courier-imap restart

Note: You should be able to edit the file using your favourite text editor via FTP however in our case the resultant file always crashed the imap service, which is why we ended up using VI.

Magento 2.4.7 is here!
David Pratt

Magento 2.4.7 Has Arrived!

Magento 2.4.7 is set to land, with the latest release due to be launched on Tuesday the 9th of April 2024. The latest updates sees over 150 performance and security fixes as well as platform enhancements and upgrades.
Read More »
DTF Digital