There are no true rules in email marketing — the technology is continually updated and behaviors change. So keeping up with the times is key. Knowing how messages are sorted, what SPAM filters pick up, and what code is supported is all part of the process of email marketing. Just keeping tabs on how people interact with their email is huge. Even guidelines for subject lines change, albeit at a slower clip than other standards.

Subject line basics

Let’s start with some of the ground rules:

  • Keep it short — You only really see 35ish characters on most mobile email apps</li
  • Avoid the SPAM filter — The basics are easy. Avoid overly salesy language like free, guaranteed, NEW</li
  • Stir up some curiosity — No one opens “Sales details inside”</li
  • Frontload your info — You need to make sure the important parts are seen first</li
  • Don’t forget about the pre-header — Add some clarification to your subject line and entice that open, you have more room in the pre-header</li

Crafting a perfect subject line

Generally, I prefer to work on subject lines last. Usually after you write an email, you can grab a phrase or two from the body content that will work great as a subject line. Just make sure they follow the rules and create some intrigue. This way you can develop a story that starts in your subject line and pays off once the email is opened.

Personally, I start freewriting — any idea goes. After a few lines, I typically have the seed of a good subject line. Except it’s usually 70-80 characters. Now comes the hard part. Paring it down.

Remember the basics. Subject lines need to be short and sweet. At this point I normally take my favorite iteration and rewrite it as much as I can. I aim for 10 rewrites, but it generally takes me less than that to get a good subject line. Do this a few more times, and you’ll have some really great subject line and pre-header pairs.

One is the loneliest number

At this point, you may think you’re done. But one subject line is never really enough. Between writing to different targets and testing, you’ll want to have some options. Most email marketers are able to A/B test subject lines to help give us writers some clues for what’s working and what’s not. That data is valuable, even if it sometimes means you’ll write subject lines that don’t seem all that exciting. Sometimes the boring stuff works.

Tools of the trade

There are a few tools I like to use for writing subject lines. First and foremost is my word processor’s character counter. And when there isn’t a character counter, I just search for one. Normally I end up here.

Even though I know how long my subject lines are, I like to see them in action. So I head to this nifty phone visualizer.

I’ve used when I need some help checking against best practices in a hurry.

To keep up with the ever-changing SPAM filters, check out IsNotSPAM. You’ll get some help, but hopefully your sender is reliable, since that carries the most weight these days.

Don’t toe the subject line

Writing subject lines is tough. Writing a lot of them at once can be draining. In the past, I’ve kept a log of successful lines and used them to create some formulas to help me when I’m pressed for time, or hit a wall. But when that didn’t work, I’ve pulled other writers in, gave them a quick break down of what’s needed, and took down some of their ideas. A fresh set of eyes always helps. Some of my best subject lines have come from outside inspiration.

They’re not called subjective lines

Remember that these 35 or so characters might make or break your email campaigns. You need to poke and prod, test and target to get the best results — always keep this in mind when writing. And if the boring stuff gets those opens, that’s ok.

Let's talk

"*" indicates required fields

This field is for validation purposes and should be left unchanged.