|Email Preferences ("SAVE" button)||Main Configuration Settings|
I've had an account with Steam for more than ten years and never received advertising email.
Recently, emails began arriving and checking my account showed I'm subscribed to everything. Valve either by accident or design re-subscribed me to everything.
I wanted to unsubscribe.
Problem is, it's not possible. The "SAVE" button is obscured by other content in the page and cannot be selected.
By contrast, on the main configuration settings page, there is no "SAVE" button. All changes take effect as you make them.
I contacted Steam support.
Briefly note this is extremely difficult to do. The support pages are basically like the vaginal passage of a Mallard duck, which because of the extremely high frequency of rape, is a maze of dead-ends to divert unwanted sperm from the egg.
Most support routes lead not to a way to contact customer support, but an FAQ or account configuration page. In the end, you give up trying to find the correct way to contact support, and hunt for any way to contact support. I filed a "billing problem" request.
The next day, support replied - sadly, I do not have the original message, but this was the reply.
Please install different browsers until you find one which works.