Your mail server handles the way users download and view their mail. Courier and Dovecot are the 2 mail servers you can choose to use with cPanel/WHM. Both mail servers support POP3, IMAP, and SSL.
On a cPanel server, there are 2 types of mail servers available; Courier & Dovecot.
Courier
- Traditional cPanel IMAP and POP3 server.
- Extremely reliable.
- Low memory footprint.
- Highly configurable.
- Excellent security track record.
- Better IMAP performance.
- BlackBerry Fastmail support.
- Ideal for memory or CPU constrained systems.
- This is the default choice.
Convert Mailbox Format
Convert mailbox settings file format to new mail server’s format during migration. When checked, the settings files for each mailbox will be converted into the format for the new mail server. This includes information about read messages, mailbox subscriptions, etc. Unchecking this box will cause your clients to lose their mailbox settings but will speed up the migration.
Simply login to the server via WHM as root & access option Service Configuration » Mailserver Selection. Select the mail server you wish to select & click save. Make sure you tick the option Convert Mailbox Format.
Note: Switching mail servers may cause some mail clients to redownload all stored mail messages for the account. This is primarily is seen with POP3 configured accounts.
