1) Update the DNS for the Domain
– Change/Add MX records to set external email server with relevant priorities
– Either remove the CNAME for mail.domainname.com(if not to be used for configuration) OR
– Edit CNAME for the domain which will point to external email server (usually provided by email service provider) OR
– Add A record for mail.domainname.com to point to external email server
This will take some time (12 to 24 hours) to propagate the changes made in DNS.
2) Once the DNS is configured to use external email server, it is necessary to de-activate the Mail service for the domain from the Plesk.
– Login to Plesk as admin
– Search and go into the Domain
– Click on ‘Mail’ (has drop down options)
– Click on ‘Mail Settings’ (other option is ‘Create Mailing List’)
– Under Mail Preferences Uncheck the option “Activate mail service on domain”
– Click ‘OK’ button to save the settings.
The Above settings must remove the entry for the domain from the following two “qmail” server configuration files.
After removal of above to entries, server will look for the external email server for that domain by fetching MX records from its DNS.