I get lots of spam from particular mailing services like Constant Contact and Mailchimp. 100% always spam from these services. Is there a way to block messages received through these services? I can see the domains in the header of the email but I don’t see an option to block messages based on info in the header.
https://proton.me/support/sieve-advanced-custom-filters
good luck
i think you would want to start with:
if header :matches “from” “somedomain” { discard; }
but i am just spitballing.
EDIT: i think there is a “reject” as well.