Subscribers should know before opting in how often you plan to distribute e-mail messages so they can determine if the intrusion is worthwhile. Therefore, newsletter sign up boxes should be accompanied by a notation that the messages will be delivered daily, weekly, monthly or according to some other schedule.

Rather than send a daily newsletter to everyone on your subscriber list, consider more targeted, and less frequent deliveries. For example, if you operate an e-commerce site that sells pet products, a species-specific weekly newsletter may be more beneficial to customers than a daily, generalized message. After an iguana owner receives several promotional messages for ferret products, future e-mails from you are likely to be deleted. Targeting guarantees that your recipient is interested in the subject matter.

If your e-business is seasonal, subscribers may expect a proliferation of messages from you during certain times of the year. In fact, they may be eagerly awaiting your promotions for fresh flower deliveries around Valentine's Day and Mother's Day. However, once the holiday has passed, you should resume your usual e-newsletter schedule.

E-mail marketing should be perceived as a service to customers, not a daily opportunity to drum up business. Earning a customer's trust will ultimately pay off in sales, and enhance your professional reputation.