Options a user can set to determine how they want to receive your messages, how they want to be addresses, to which email address message should go and which messages they want to receive from you. The more preferences a user can specify, the more likely you’ll send relevant email.

The 3 Things To Avoid When Emailing Your List
When you decide to have an opt-in list, it is not just a matter of sending your subscribers your promotional newsletters or catalogs.