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How to Develop Winning Subject Lines?

Jelena RumiancevaBy: Jelena Rumianceva, Account Manager, Emarsys

As I opened my inbox earlier today and saw 367 emails, I once again thought about what made me open certain emails before others, and why there were some I deleted straight away.

I know that I always look at the subject line first as a habit, before I even see who or where the email comes from.

In these times of busy inboxes, high spam rates and fraud alerts, it is getting challenging to keep high levels of engagement across your recipient base. If you’ve followed all the deliverability rules and made it into the inbox of the recipient, it’s a shame if your email goes unopened because of a dull or irrelevant subject line.

Writing a winning subject line is not easy however and is very specific to your brand and recipient demographic. Having said that there are always basics which should never be forgotten:

1. Keep it short and to the point
Very often subject lines are considered to be a short summary of an email and tend to feature the most interesting information or best-selling products in them. This could be the wrong strategy as most of the information will never be read by your recepient. For the benefit of your brand in the eyes of your valued customer and the ISPs – keep your subject lines under the limit of 60 characters. And if you are ever looking at how long your subject lines should not be, have a look in your junk folder!

2. Be adventurous and enthusiastic
Experiment with different structures of subject lines. Do remember however that before you reach the inbox of the recipient you will need to pass all the spam filters of the ISPs. Therefore be deliverability friendly and anti-spam compliant

3. Be consistent, but not boring
Remember that your subject line should always reflect the content of your email. If your brand is consistent with its offerings, you will not have a problem with delivering what is expected from you. You may however see your open rates decline if you become tedious with using similar subject lines and get easily ignored by your recipients

4. Test your subject line
A/B tests are too easy and quick not to be used. Using the same campaign and simply changing the subject line to test 2, 3, 5 or more combinations will give you a good insight on what is working for your database – in combination with your brand offering during specific times. I am firm believer that subject lines should be tested at all times, as with rapidly growing and changing consumer interest and market development, there always will be a slight element of change.

5. Monitor the performance
I often see different companies tracking the performance of subject lines on a campaign by campaign basis, without comparing the results post-campaign – and I believe that this is where valuable insight is being lost. Constantly log and monitor the performance of all your subject lines; this will give you the understanding of what subject lines perform the best at different times of year, in conjunction with different creatives and messaging.


  • Suhayl Hendricks

    Very interesting opinion, relevant in today’s email campaigns and emphasising the importance of the subject line. A book is viewed by its cover, an email by its subject line. Getting it right will keep your recipient engaged and happy.

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