Seven rules for writing a stellar email subject line

Writing the subject line is often the last and most hurried step before sending an email, when it should actually be the other way around. These are very much a mission-critical element of your communications strategy that you shouldn’t leave until deadlines are looming. In fact, those first few characters are the doorstep to your emailing success; since it’s all you have to catch the attention of your reader, entice them to open your message and take action.

As you plan an email send, thinking first about what will go into the subject line is crucial. Potential recipients use the subject line as a litmus test to decide whether to open or delete an email or report it as spam; which is why it can make or break your whole campaign.

Subject line character limitations make them a challenge to write, but it’s worth doing well because a good subject line can get your email opened immediately. Your subject line is all your subscribers have to go on until and unless they decide to open your message. So if you want to be able to leverage your mailing list in the best possible way (even if you have a very large amount of subscribers) you have to learn how to write appealing subject lines.

With this much at stake, marketers need to follow a couple of fundamentals to ensure that their subject lines are as good as gold:

Rule 1: Know your objective
Since a subject line distills the essence of an email, consider writing it first, as this will keep you from straying off point. Think about what the objective or end goal of your email marketing programs is.

In most cases your end goal is not necessarily high open rates, but to have subscribers take a specific action. Determine what that one action is and make sure all components of your email, especially the subject line, will highlight a clear path to the objective.

Rule 2: Study the media
Good subject lines communicate and captivate in a small amount of space. News headlines highlight a story’s most important point briefly, while taking the audience into consideration. A headline must be short and intriguing enough to compel people to read the entire article.

Subject lines, where possible, should clearly state what your reader can expect from your email, what’s in it for them or what you want them to do. If you’re stuck at square one, emulating the headlines from newspapers can be a good starting point for your emails.

Rule 3: Key information first
It’s important to mention the most significant information first when it comes to both your subject line and the email body copy itself. You only have one opportunity to make a first impression. You need to convey one compelling line that prompts the recipient to both notice and open your email — which is difficult to do.

If you have an answer about what would make your readers care enough to open your email in 50 characters or less, you probably have your subject line, or something close to it.

Rule 4: Lead without misleading
While it’s important to create a sense of magnetism and urgency with your subject lines, it’s even more important to maintain your company’s dignity with every communication. This means never misleading people with the subject line in order to get them to read further.

Don’t stretch the truth, make grand claims or offer more than what you can or intend to deliver. Don’t show one thing and deliver something different from what you described. Promising more than what you can produce is a quick way to drive people to opt out.

Rule 5: Personalise
Personalised subject lines are a simple way to secure the interest of your recipients. Where appropriate, using someone’s first name can be a very effective form of personalisation.

If you want to include this in your personalisation strategy, take the time to go through your database and make sure that you actually have the first name for every record and that the names in your database use proper capitalisation. Subject lines can also be personalised based on the preferences of the recipient; or on their interests, past purchases, website visits, links clicked or more or less any other commercial data you have captured about him or her.

Rule 6: Make it deliverable
The greatest factor influencing the deliverability of your email is your reputation score with Internet Service Providers (ISPs). If enough of people mark your email as spam, or if you routinely use words that trigger spam filters, your ISP reputation will get damaged and your emails will end up in the junk folder netherworld.

There’s a fine line between a catchy line and a spammy line, so run your email subject through a content checker to identify any spam-like words, phrases or construction. Your email will have to successfully pass through a number of filters at different points. Don’t leave it up to chance; use a content checker will tell you what to avoid.

Rule 7: Test, test, and test again
Testing subject lines give you better data and ultimately better campaign results. If you’re dealing with a big list of names, run tests to a small group before sending to your full list. An A/B test involves splitting a list into two different headlines, without making changes to any other part of the email, to see which had the better result.

Use the metrics from each segment to determine which subject line delivered the highest open rate or click-through rate. Every email send is unique, so you will need to repeat this testing phase every time you send a message, to consistently identify the higher-performing subject line.

Subject lines should be focused in a way that reflects the needs of your audience and that’s connected to the purpose of your email. You want these to be relevant and on target, but at the same time you should be creative, practical and, most of all, be absolutely believable.