I suggest you add unsubscribe links to your spam emails.

What is CAN-SPAM? Staying compliant with the CAN-SPAM Act is key to staying in business. But, what is the CAN-SPAM Act? Enacted on December 16, 2003, the CAN-SPAM Act is a law that sets the rules and regulations for all commercial emails. It gives users the right to opt out and unsubscribe from your email communications at any time. Non-compliance or violations result in heavy fines and penalties. Here are the requirements posed by the CAN-SPAM Act: Senders must not email recipients who have previously opted out of their communication. Senders must honor and remove opt-outs from their email list within 10 business days. Each email sent must have an opt-out mechanism that makes it easy for consumers to opt out of all future mailings. Each email must include the physical address of the individual or business sending it. Senders must not use deceptive subject lines and false or misleading information. Senders must identify that the email is an advertisement.

Does that apply when emails are part of your account settings?  There may be exemptions to that particular rule (I am definitely not a lawyer).  Either way, if you check your account settings, you can turn off emails there.