E-marketing is decreasing in usefulness due to spam, fear of viruses and sheer volume. However, your efforts can be more effective by using these tips:
The best application for e-mail marketing is to communicate with existing customers/prospects rather than troll for new prospects. Spamming is a no-no.
Understand how to use search engines effectively, but do not pay for preferred position.
Never use rich media (audio and/or video) within the e-mail—link to a rich media web page.
Keep the e-mail short—no more than one screen and never include an attachment. Link to pages on your web site to give them more information.
Don't look like a spammer—keep your tone friendly and informative. Avoid overblown (hyped) language.