- Plesk for Windows
- Plesk for Linux
One of the following may apply:
- Spam filter option for newly created mailboxes is turned off by default despite the fact it is turned on server-wide: Switch on server-wide SpamAssassin spam filtering and Apply individual settings to spam filtering options are enabled in Home > Tools&Settings > Spam filter
- Spam filter management option is not granted (it is unchecked) in Home > Service plans > service_plan > Hosting Parameters
- Mailbox created under Administrator account in Home > Subscription > example.com > Mail has Spam filter disabled by default.
- Mailbox created under customer's account in Website&Domains > Email addresses has Spam filter enabled by default (this can be verified by logging under Administrator account since permission to manage Spam Filter is not granted for Customer)
This is Plesk internal issue with ID #PPPM-6031, which is planned to be fixed in future Plesk updates.
As a workaround, enable Spam protection from the administrative account or enable Spam filtering management permission in the service plan.
In order to enable Spam filter by default for all created mailboxes both under Administrator and Customer accounts, follow instructions here:
How to enable spam filtering for all newly created subscriptions?