These are options for the MX Entry for a domain in cPanel. Essentially, the option you choose tells cPanel how you would like the mail services for the domain handled.
Mail Exchanger Options:
- Unless you have a particular setup that needs these explicitly stated, the recommended option is “Automatically Detect Configuration.”
- Local Mail Exchanger: Handle all mail sent from the server to this domain locally; i.e. – deliver it to the mailbox that is on the server rather than remote mail service.
- Backup Mail Exchanger: Handle all emails like a remote mail exchanger, unless the remote service is unreachable, in that case, handle it like a local mail exchanger. (For example, if you have Google as the mail service for the domain, then send the emails to Google’s servers like the remote mail exchanger. If for some reason Google’s servers are inaccessible, then deliver the mail locally, as in the local mail exchanger option.)
- Remote Mail Exchanger: Handle all mail sent to this domain remotely; i.e. – deliver it to the mail service determined by the domain’s MX record. (For example, if you have Google set up as your mail service, deliver the emails to the mailbox on Google’s servers rather than your local mailbox.)