Email marketing is an integral part of a successful online promotional strategy. If you've ever bought a book from Amazon, a plane ticket on Expedia, or any other product online, you may have opted to receive updates on special offers or promotions.

This is successful email marketing. You've opted to receive updates from these companies. You've given them permission to send you an email at a later date. This is how successful email marketing starts—with you as a business getting permission to send someone an email.

Your primary email marketing tasks will be to send out important information about your business niche, encourage existing customers to make more purchases with promotional emails and attract new customers with giveaways.

There's one caveat to this…

Don't make every email promotional even if you stated that in your terms and conditions. Why? Most people are hit with promotional only emails everyday. Make yourself stand out by GIVING SOMETHING AWAY first.

Depending on the size of your business, you should target emails at customers based on previous purchases. Many of the larger online businesses have been successful because they're able to offer products that match customer interests. If your product is in a well-defined niche, you may not have to worry about matching broad interests.

Your email's reply address and subject line are extremely important. That's because you still have to get the message opened once it's in the recipient's inbox. Even though you're not spamming, you still have to overcome spam's stigma.

Use a domain related email address with a real person's name. For example, if you sell bookmarks and your domain is mybookmarks.com, the reply address should go to bev@mybookmarks.com not bev123gh5@aol.com. Spam messages use random, spoofed email addresses that don't look legitimate.

Use a subject line that will appeal to the recipient. Use a standard convention that users will learn to expect. For example, if you offer a monthly special, make that clear in your headline (e.g. "Bev's Monthly Bookmark Special").

When you write the content of the email, you want to encourage the reader to buy the product but you don't want to go overboard. Avoid the hard sell to existing customers.

They bought from you once and will again if you respect them and really delivered.

Another important point is Website links in your messages. Spam filters are notorious for filtering out emails with too many links—especially redundant links. Only put as many links as necessary to lead people to your Website.

Determine which day works best to send out your email. Don't send messages in the middle of the night, unless, of course, it’s the ONLY time you can because your message will be waiting—along with countless other mails—when the receiver checks their email the next day. The same goes for holidays and long weekends. Early evenings work best since most people have cleared out the junk by then.

Finally, DEVELOP A RELATIONSHIP with your list.

Treat them with respect and honor their in-box. You DON’T want to be another reason for them to press delete.