SpamAssassin check should always happen before redirect
According to https://support.plesk.com/hc/en-us/articles/115000786914-How-to-enable-SpamAssassin-spam-check-for-forwarded-emails-on-Windows when the option "Apply individual settings to spam filtering" is enabled, filtering of forwarded emails is not performed and additional steps are required.
Please, make it so that no additional steps would be required.

Thank you for your input! We will consider this functionality for the upcoming releases if it becomes popular enough.
Everyone, please continue voting for this feature if you consider it important.
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IG
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Miomir Besarabic commented
Not only for Windows but for Linux too. We have huge problems with forwarded mails without any Spam-Filter check which allow a lot of Spam to be forwarded.