Is it possible to configure relayhost in Plesk with Postfix?

Question

Is it possible to configure relayhost or smarthost in Plesk with Postfix?

Answer

Smarthost configuration is possible starting from Plesk Obsidian 18.0.64.

Warning: If you have already configured a smarthost/relayhost manually, enabling the smarthost feature in Plesk will overwrite your existing configuration. Refer to this documentation here.

Note: With some SMTP relay services (for example, SendGrid), mail forwarding will no longer work if a smarthost is configured.

Follow these steps to configure the smarthost in Plesk:

1. Log in to Plesk
2. Go to Tools & Settings > Smarthost (under "Mail")
3. Select the checkbox "Send users' mail via a smarthost"
4. Enter your Smarthost connection details
5. (Optional Step) check if the connection to the smarthost can be established by clicking Check Connection

Note: It is necessary to update the SPF record to authorize the smarthost to send emails on domain's behalf. Refer to this article: How to change a DNS record on a Plesk server globally for all domains?

Additional Information

Configuring a Smarthost or Relayhost