Deactivate local e-mail service
When using an external mail server in combination with a hosted domain on a different web server, it is necessary to deactivate the email service in order to transfer outgoing emails from the web server to the actual email server.
Problem description
If you are running the Plesk Control Panel on a server, an e-mail configuration is automatically created as soon as you add a new domain. If this domain uses a different email server, outgoing emails from the Plesk system are no longer delivered using the MX (Mail Exchange) DNS entry, but are delivered locally via the Plesk server.
Solution
By deactivating the local email service of the domain, the local email lookup is deactivated and outgoing emails are delivered correctly via the associated MX record.
Disable service in the Plesk Control Panel
To disable your email service, you must first log in to your Plesk Control Panel.
To do this, click on the desired domain under Websites & Domains and then on the Email tab to configure the Email settings.
To deactivate the local e-mail service, select the option "Disabled for incoming e-mails " under Enable e-mail service on this domain.
If you have activated the option, you can confirm the adjustment of the e-mail settings by clicking on "OK". Outgoing emails from this server are then no longer delivered locally, but are correctly routed to the target server via the MX record.