I've found it useful to email management if certain sales people refuse to stop contacting you. 

On Sat, Aug 22, 2020, 1:34 PM Bryan Holloway <bryan@shout.net> wrote:
Tired of receiving spam from these jamokes.

https://www.atmarktrade.com/

Atmark Trading out of Chicago.

Have tried unsubscribing numerous times; e-mailed their "info" accounts
to no avail.

My only recourse, now, is to shame.

Doubt it will do any good, but if anyone has a contact who can actually
get us off their ridiculous mailing-list -- 3 to 4 e-mails a day --,
well, I'm all ears.

If not, well, don't do business with these bozos.

/rant

Happy Weekend ...