We created a website, connected a payment system, pay and the customer receives a check in the mail, but the mailing does not come. What to do?
How to unsubscribe from mailings from unnecessary sites?
Constantly receive mailings and advertisements from sites I don't need
How to unsubscribe from Dengomir mailings?
What is a postmaster, is it necessary to connect it if you send letters through the mailing service?