Email Subject Line Best Practices

19 December, 2014

With hundreds of new emails in our inbox to sift through every day, what makes you decide to open an email? It’s the email subject line, as it is the first impression of the email and a good indication of whether the email message is valuable or a waste of your time.

If you are an email marketer, you want your email campaigns to be opened and ignored. According to Convince & Convert, "33% of email recipients open an email based on subject line alone". So it makes sense that you spend time crafting the best email subject line possible. Below are my 15 email subject line best practices for crafting effective email subject lines to increase your email campaign open rate.

Email Subject Lines Best Practices

  1. DON’T WRITE IN ALL CAPS AND INCLUDE EXCLAMATION POINTS!!! Not only is this obnoxious, but you’re more likely to end up in a spam filter.
  2. Avoid long subject lines. 20 to 30 characters are plenty because consumers won’t read past that, and most of the wording will likely be cut off on the screen, particularly on mobile devices.
  3. Don’t use spammy words like FREE or open immediately, Don’t use symbols or strange characters Don’t oversell in the subject line.
  4. Test your subject lines. A/B test your subject lines to see which performs better. If
  5. Test and see if people respond better to your company name as the sender or employee’s name. 
  6. Try framing subject lines as a question or with another call to action. Give the user an idea of what is in the email. 
  7. Writing minimalistsimple, and to the point, email subjects will get the most response. Users need to immediately determine which emails they want to read and which ones should go in the trash. For example (5 Ways To Better Manage Your Time)
  8. Most companies send emails with dry, uninspired, and boring subject lines. Funny and humorous subject lines will make your emails stand out from the crowd. The reader will assume that if your subject line is funny, your email will be too. (Customer Surveys: Baby Got (Feed)back)
  9. Controversial and debatable subject lines will always grab the attention of your reader. (CPC Advertising Sucks: How To Quit Wasting Money)
  10. One-word email subject lines are decisive and stand out from all other emails in the reader’s inbox. Barack Obama proved the effectiveness of this strategy with the subject, “Hey.” (Yikes! ... Whoops… or Yikes)
  11. Numbered lists subjects have a higher open rate because they are easy to read and quick to consume. (Top 10 Tips for Successful WebEx Meetings)
  12.  Questions open a communication channel between you and your readers, making your emails more friendly and conversational. (Ever Wonder If Your Boss Actually Likes You? Here’s How To Find Out.)
  13. No one likes to be missed out on. So if you have promotions, encourage readers to act quickly. Subject lines that portray a sense of urgency like  “Limited Time …, Last Chance …, The Final …. Don’t Miss” have higher open rates. 
  14.  “How” is one of the most effective words in email subjects. It’s an indication that your email will be informative. If you know what your customers are looking for and sending them a  “How to…” email will result in a higher open rate (How To Protect Your Mobile Screen)
  15. Go further than simply adding your reader’s name to the subject line. Target your emails to specific customer attributes such as Location-specific, Gender, Stage in the buyer's journey, Age, Birthdate, etc. will result in high open rates. Personalized (5 Best Lunch Deals In Santiago) 

I hope to have presented some useful best practices for email marketing subject lines to help your email campaign achieve a higher email open rate.



My name is Izzy and I am a co-founder of IDS, an award-winning HubSpot Solutions Partner. I lead our team of consultants who provide professional guidance to help businesses implement the HubSpot CRM platform migrate, integrate their tech stack to HubSpot to create a seamless environment for sales reps to use. There is nothing I love more than solving the challenges that come up when someone wants to migrate an old system or integrate their tech stack with HubSpot - it's like a puzzle!

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