Even though e-mail is one of the oldest ways of connecting with others over the Internet, some companies are still asking, “How do we make sure that our e-mails get read?” That question’s really not too surprising, though, since e-mail has evolved to include spam filters and consumers have gotten great at tuning out advertising (and nothing says advertising more than a direct e-mail with a title that reads, “FREE SHIPPING”). Give ‘em a clever subject line time and again, on the other hand, and your chance of getting people to open your e-mails goes up dramatically. Here’s how.

Set expectations and stick to them

When you get people to sign up for your mailing list, let them know what kind of mailing list they’re signing up for. The same goes for sending e-mails out to addresses on a list that you procured. If you’re writing a regular newsletter, you should inform customers rather than sell to them. On the other hand, if you’re writing eBlasts to subscribers who are expecting to receive promotions, then selling to them is the right decision. Marketing 101 is about knowing your consumers, but if you want them to open your e-mails, they should also know you.

Use language very carefully

A tactful word choice makes a huge difference in reaching your target audience. The word “free,” for instance, commonly falls into spam traps online. Other words that are less commonly used but mean the same thing, however, can get past spam filters.

Your recipients aren’t guaranteed to read your message just because it makes it to their inboxes, though. While terms like “percent off,” “reminder,” and “help” are innocuous to natural inbox-filtering processes, they still commonly fall on deaf ears. To get past the gatekeepers, you need to frame your subject lines in different terms. And that requires a little strategy.

Justify every newsletter and e-mail

One of the best ways to build your brand in a direct e-mail marketing campaign is by making every e-mail count. In other words, don’t make the current newsletter you’re writing regurgitate what your last one said (remember the “news” in “newsletter!”). If this means releasing one every month instead of every week, that’s okay (and, at times, better). Making sure that each one is different and released on a regular basis, however, will allow your recipients to look forward to each one.

Keep it personal, timely, and under 50 characters

Subject lines that hit a personal chord are good to write because recipients naturally are connected to the message. Additionally, you can offer timely and useful information without selling (party invitations are especially good at hitting all three checkpoints). While keeping the above rules in mind, make sure not to forget this one: email subject lines that usually get the highest open rates are the shorter ones.