- Plesk for Linux
Is it better to choose Dovecot or Courier IMAP?
For IMAP and POP3 delivery, Courier IMAP or Dovecot can be used. Plesk recommends using Dovecot. For additional information refer to Plesk documentation.
In general, the choice itself should be made based on your environment and the specific business needs. Both these services have features that may help to configure mail delivery more efficient depending on the business structure and server configuration.
You can switch between IMAP and POP3 servers under Plesk > Tools & Settings > Updates and Upgrades > Add/Remove Components > Mail hosting features or in Tools & Settings > Mail Server Settings. Plesk will start using the new mail server without any need for server restart. You can select another mail server at any time later.