[ValtteriL]

I usually just reject mail from the address or even the whole domain on the email server level. This causes them to receive mail rejection notifications and my inbox stays at zero. Zoho workspace makes this easy to do.

I could just block them silently, but reject notifications add to their spam score on email provider level and may help them reconsider their approach.

Curiously, one spammer rotated over 10 similar domains in a span of 6 months as I kept blocking them. Assuming their spam software did it automatically.