Boost Your Open Rates 2x with These Email Subject Line Hacks

With an ROI of $38 per every $1 spent, email marketing still leads the league among the top channels for marketing and is 40 times more successful at acquiring new clients than Twitter and Facebook.  And the subject line is one vital piece of the puzzle.

A large percentage of people decide whether or not to open an email by looking at subject line alone. And higher open rates lead to increased subscriber interactions in your email campaign.

Take a look at some helpful stats on email subject lines (Source).

  • 47% of email recipients open email solely based on subject line
  • 69% of email recipients report email as spam based solely on the subject line.
  • Subject lines that create a sense of urgency and exclusivity can give a 22% higher open rate.


With that out of the way, here are seven good techniques to help you boost your open rate.


Pass through Spam Filters.

Regardless of how well-crafted your subject lines are, they won’t get viewed, much less opened unless they land in the inbox of your subscribers.

Not enough people interacting with your emails, or flagging them as spam, and deleting them without opening is not good for your spam score.  Some do’s and don’ts to help you increase your deliverability:


  • Deceptive/misleading:  Avoid misleading subject lines such as clickbaits, putting “fwd: ” and other deceptive messages
  • Spam-like words:  Choice of wording in subject lines is one important factor that affects your email spam score. There are spam-trigger words you should use less of or avoid altogether. An example of these words include “free”, “fast cash”, “act now”, “credit” etc.
  • All CAPS: Writing your subject lines in all CAPs doesn’t look professional and increases your spam score.
  • Keyword stuffing: Make sure your subject lines sound natural and avoid cramming keywords



  • Stay true to your brand: Keep your subject line writing style, brand voice, and tone consistent.
  • Increase engagement: Get more subscribers to open and engage with your email, so your deliverability rate increases, which in turn, ensures that more of your future emails pass through the spam-filter
  • Spell check: Correct spelling and grammar are important in ensuring your emails land in the inbox folder.
  • Keep it short: Try using subject lines not more than 6-10 words in length to decrease your spam score.


Identify your optimal length.


Identify your optimal length.

When it comes to subject line length, there’s no clear winner between short vs. long emails since there has been cases where shorter subject lines outperformed shorter ones and vice versa.

According to a research conducted by Return Path on 3,000 retail brands, “subject lines 61 – 70 characters long had the highest read rate (17%).”

However, there are some factors to bear in mind to find the optimal length for your campaign.  


Consider mobile friendliness.

With 55% of email opens occurring on mobile devices, you should take mobile email into account when creating your email campaigns.

Generally, shorter subject lines are better off for mobile-optimized emails.


Check your past email performance.

You can check your email analytics to gauge the length that’s optimal for your email readers.

Most email marketing service providers today have a feature that shows you the percentage of people who open your emails on the different devices.

Based on that data, you can find observe which devices most of your readers use the most, and settle on your ideal length accordingly.


Here’s a helpful graphic to help you with that:


Use personalization.

Brands like Amazon, Tripadvisor and Yelp are some companies known for their clever use of email personalization.

They keep tabs on the browsing habits, previous purchases, and interaction of their customers on their site, which allows them to send out emails with very tailored product recommendations, call to actions, and value.

Now you may not have the tracking technology or resource of the big retailers. But you can match your subject lines to your subscribers’ needs by learning about your subscribers’ needs, and interests by collecting data such as through segmentation, surveys, etc.

Besides, a research by Experian indicates that addressing your subscribers by name in subject lines boosted open rates by 29.3% on average.

The lift is greater for industries like consumer products and travel, and seemingly that has to do with the reliability of the data.


A downside with adding subscriber names in subject lines.

There’s a likelihood of subscribers either:

  • leaving the first name field blank, or
  • entering wrong details, such as fake names, or random words or letters when they sign up


In such a case, some email marketing services have features that replace missing FNAMEs with generic greeting words like “Hello”, “Hi” etc. You should consult your email marketing provider if they have such features.

In addition, to get around the issue of subscribers entering fake details, some email marketers suggest to look at your list of subscribers in your email marketing software, and stop using first name personalization if many of your members have fake details.


Personalization beyond first names.

Beside first names, there are many ways you can make your subject lines targeted to your subscribers including, location based (such as zip code tags), trigger emails (or based on subscribers’ activity on your site), purchase history, and browsing history on your site. Here ‘s an examples:


Make use of symbols cleverly.

The shiny, and at times peculiar emojies that are starting to trickle in your inbox are more than just a fad.


A thoughtful use of them has been proven to increase open rate.

To stand out in today’s crowded inbox of consumers, you can use symbols like emojies and Unicode symbols in a way that doesn’t destruct from your message.

A word of advice on FulcrumTech says to:

  • use symbols with judgment
  • use ones that resonate with your brand
  • add them in the first twenty characters of your subject line and test


Get seasonal with your subject lines.

Add in the mix seasonal email subject lines and make your email marketing timely and current. Some ideas include tips, offers, or deals linked to holidays (like black Friday’s and Cyber Monday’s), seasons, or other major events in your industry or in the news.  Some examples for inspiration:

  • Simpleology: 10x More Important Than Trump (a few days after Trump’s victory)
  • Start Making More $$$ This Holiday Season
  • ShareASale: Boost Your Black Friday & Cyber Monday With These Tips
  • Get Ready for Internet Privacy Week
  • Jess Dang: your Thanksgiving prep kit


Don’t forget to test.

In the world of emails, what works well for one business, may not work as effectively for another. This is due to factors like industry or niche, relationship level with list members, and so on.

Running split tests on your subject lines is an effective way to determine what goes down well specifically for your audience.

You can conduct tests on elements like length, personalization, symbols, curiosity subject lines, numbers etc. so you can use more of the winner elements.



Unquestionably higher open rates mean more click-through’s, more engagement, and higher transaction for your campaigns.

That’s why you should use every effective technique and test, since creating a catchy subject line is important. But equally important is the person or brand sending it; since over half of email readers open an email based on who is in the ‘From’ field.

Build relationship and get your email members to trust you to and make them anticipate receiving emails from you. You’ll improve your success with email marketing.


Author’s Bio: Masroor Ahmed is a conversion optimization analyst at where he helps online businesses in improving the conversion rate of their websites.