If possible, you should keep a record of how and when people opted-in to your list, so that if someone ever accuses you of sending spam you can easily point to the time and date that they requested to be added to your list. In every email that you send out, make sure that the customer knows how to get off your list. If you only send email to your list occasionally, people may forget that they opted-in to your list. In this case, it is best to state how they got on your list within your opt-out clause. This way the recipient will recognize who the mail is from before they open the message.
Legitimate businesses identify themselves clearly in the email headers.
By creating this alias and giving your readers a place to be heard, you can often resolve your subscriber problems before they report you to your ISP. 5. Make sure your list is fairly recent. After time, people tend to forget that they opted-in to a list and can easily mistake a message they opted to receive for spam. As a general rule, you should send them something within a week or so of opting-in and at regular intervals afterwards. Coordinate your mailings with your ISP Contact your ISP before you send out a large mailing so that they will understand what's happening when they see the burst of email traffic from your site.