Email marketing
   If you have your own website you probably already have the capability to create, manage and send your own mailing lists. However, making sure your email server complies with all the best practices in order to look like a trusted source so your mail does not appear in your user's spam folder is tedious and ever changing. Paying a commercial company to get you a 99% delivery rate may be worth it to you.

Aweber
Aweber.com Starts at $15 per month for 500 addresses.

Constant Contact
Constant Contact Starts at $15 per month for 500 addresses.

Get Response
Get Response.com Starts at $10 for 250 addresses or $14 per month for 500 addresses.

Emails for Small Business with Constant Contact