To effectively market by email you need permission to contact your readers. This can be done by having a sign-up box on your website or even a sign-up sheet at your location. It is very important to comply with the federal laws. If you don’t have permission, don’t send an email.
Some of the US Federal requirements when sending commercial emails are:
1. A real, clearly identified “From” address
2. A real, working “Reply To” address
3. Clearly defined content
4. A real, working unsubscribe link
5. A clearly identified address
Using an email campaign program such as Constant Contact or MailChimp can help you stay spam-compliant.