Net Atlantic Inc. Professional Email Marketing and Email Deliverability Experts

Professional Email Marketing

Email Subject Lines That Work

by Andrew Lutts

Following are some musings on email marketing best practices, straight outta the Net Atlantic Compliance Corner. Everybody puts Steve in the corner - but that's where I like to be, so it's okay!

Today I'm going to talk about best (and worst) practices for subject lines.

The subject line of your mailing is often an afterthought, but it can play a very important part in how your overall mailing performs. Used correctly, the subject line can improve inboxing, as well as maximize open rates, conversion rates and even sales.

Take a look at your own inbox, and the various subject lines in the mailings. Some will be so compelling that you'll want to open them immediately. Others might interest you, but don't convey a strong sense of urgency, so you'll probably read them later. Still others will not interest you at all. Not only will you delete them, you may even mark them as junk!

All that said, what you'll notice about the most compelling subject lines is that they have many of the same characteristics in common. For example:

They are not “War And Peace”. Subject lines aren’t meant to be the whole email! Keep them clear and concise. As a rule, subject lines shouldn’t contain more than 45 characters (including spaces), and they should consist of between 5 and 8 words. Most email providers automatically cut off (or truncate) subject lines after a certain number of characters anyway - so keeping them short is just a good rule of thumb.

They have a benefit. Tell your readers what they can get out of reading your email.

There are no symbols. Not all email providers and services display symbols properly, so substituting letters for symbols like @, & or % isn’t a guarantee that this is how it will appear. The use of symbols like this in a subject line could also trigger filtering on the receiving end. This will cause an ISP or receiving domain to deliver your mail to the spam / junk / bulk folder. And you definitely don't want that.

They get your attention. Make the subject line enticing. Compel the recipient to open your email and read more. Make the subject line a teaser of what’s to come in the message.

They are relevant. The subject line should be relevant to what the mailing is about.

They don't contain excessive capitalization. It may look right at the time, but recipients may find it annoying and decide not to open your mail. Follow standard grammatical rules for capitalization (check out Scribendi for more on this, and other good grammar guidelines).

They are personal. Make your email stand out and unique to your tone.

They don't include certain "trigger" words. The following words and phrases, and other similar terms, should not be used in your subject lines, as they tend to cause filtering:

  • Free
  • 50% off
  • Earn money
  • You're a winner 
  • Compare 
  • Amazing
  • Loans 
  • Get paid
  • Don't delete 
  • Why pay more?
  • STOP!
  • Satisfaction guaranteed
  • Join millions
  • You've been selected
  • Act now/ call now
  • Double your income
  • Information you requested
  • All natural

I hope I've convinced you to pay more attention to how to craft a great subject line. It truly is some of the most valuable real estate in your email. If you follow the tips above, I promise you'll be well on your way to realizing the full potential of your subject lines.


Net Atlantic's Email Subject Line Grader