Some of the best email marketing practices, which are now also legal requirements, can be viewed in the Keeping It Legal section of the website.
In addition, MailMask.net recommends that the following practices be followed:
Only send email to users that have specifically requested to be added to a mailing list. For an example, see the Opt-in Lists section of the website.
NEVER pre-check email subscription boxes on sign-up forms. These boxes should be un-checked by default.
Never buy a pre-existing mailing list.
Before signing up, let the users know approximately how many emails they can expect to receive from you. Don't exceed this limit.
Let users know that you follow a best-practices list. Keep them informed about your email marketing procedures.
Don't require users to enter a password when they want to unsubscribe. Make the procedure as straight-forward as possible.
Include the tag [adv] as the first five characters of the email subject line
Following these practices will ensure a productive and happy relationship with your customers. For more information, be sure to look in the resources section.