How to stop spam emails in the Snappymail?

Hello. This is the additional discussion of the post Can we block an email address or domain on Snappymail?.

In the previous post, we choose the Spamassassin to prevent us from receiving spam market emails, but it fails, every spam email comes with same username but totally different domains. Can anyone give us a clues to stop it? Thank you.

spamassassian is an option for this use that