This is the sixth article in a six-part series on email marketing. Read part five.

Your strategy is in place. Your list is built. You’ve written compelling content and you have an attractive design. The final decision – when to send your emails. You have to consider both timing and frequency.

Regarding timing – let your marketing plan be your guide. If holiday sales are critical to your business, for example plan accordingly. Gift ideas, shipping options and promotions will be most useful information to your recipients at Christmas, Mother’s Day and other holidays.

For business-to-business emails and for companies with long-lead times, think about a campaign that educates and cultivates topics in advance of budget planning for the following year. Long-range and complex sales require equally thoughtful marketing campaigns. With careful planning and the right content, this kind of marketing can become a powerful tool in your sales efforts.

As far as the best day to send messages, it really differs depending on the business. General trends tell us that if the message is professional in nature and is read at work, send it on a Monday or Tuesday. If the message might be read at home and focuses on spare-time activities – Sunday is a good bet. In general, emails are more likely to be opened when sent earlier in the week. However, depending on the nature of your content – other days might be a better fit.

What about frequency? Your subscribers know best how frequently they want to hear from you. In fact, if they find you in their inbox too often, they’ll let you know by unsubscribing. To prevent that from happening, consider asking your recipients about perfect frequency. Test and then ask those who unsubscribe about their reasons for doing so.

A general rule of thumb is that communicating less than every other month is likely not enough and anything sent more frequently than once a week may be too often. That is, unless your subscribers specifically agreed to more frequent mailings they will tire of hitting the delete key and eventually unsubscribe – even if they like your content.

Again, the goal of email marketing is to increase conversions of readers to “buyers.” So, it’s best to think in terms of quality, not quantity. Build a program that is focused on the needs of the people who want your product or service and you’ll see an increase in your sales and an expansion in the number of customers you have.

It’s a critical part of the marketing mix.