E-mail marketing is still your best direct online marketing channel, and that’s not going to change any time soon. But it can also make people hate you in a hurry. Here’s how to maximize results and get some customer love at the same time:

1. Be polite. Use an opt-in list. ‘Opt in’ may not mean they said ‘please e-mail me’. It may mean they said ‘please contact me’. But regardless, only e-mail folks who indicated they would like to hear from you. The one exception: We’ve had good results e-mailing past customers, regardless of opt-in, but only if the message is short, sweet, and has a great incentive.
2. Obey the law. To comply with anti-spam regulations, you must have: Your mailing address in the e-mail; a clear unsubscribe method; a subject line identifying the e-mail as an ad; a working ‘reply to’ e-mail address.
3. Keep it short. Make sure the call to action is clear, and that it will show up in the preview pane of most e-mail software:
   
4. Measure and test. Try different subject lines and headlines. Send your e-mail out to small parts of your list, first, to test the different ‘recipes’. Track how many folks open your e-mail, click through to your site, and make a purchase. Then use the best combination of subject, headline, etc. for the rest of the list. If your e-mail tool doesn’t let you track opens and clicks, get a new one. We use WhatCounts, and I’ve been very happy with them. Another great one is Campaign Monitor.
5. Finally, do resend to those who don’t open the first e-mail! 3-5 days after your first e-mail, retrieve all of the e-mail addresses of folks who didn’t open it. Resend the campaign to them. We’ve seen a 25% increase in clickthru and conversion rates.

These rules let you play it safe and earn money, too: I’ve used these pointers for years, and we’ve never had a spam complaint filed against any of our clients.

Happy e-mailing!