how not to write your email subject line for ecommerce

How NOT to Write Your Email Subject Line for E-Commerce

The subject line is arguably the most important part of your marketing emails.

It’s the first thing that your recipients will see before they even open your email. Never mind your beautiful email design, personalized product recommendations or clear call to action if your subscribers don’t open your email because of your subject line. 35% of email recipients open emails based on the subject line alone. While that seems like a low statistic, it’s more than 1 in 3 of those in your email list.

In this blog post, we don’t necessarily want to tell you how you should be writing your email subject line. We believe that it’s totally dependent on your brand’s voice and style, as well as what your marketing email is about, and who you’re targeting.

Additionally, if every single email marketer were to use the same formula for their subject lines, your email won’t be standing out in people’s inboxes. This will result in a decline in your emails’ open rates, which is definitely the last thing that you want.

Instead, we want to suggest a few things you should avoid doing with your email subject lines.

Don’t make your subject line too long

There are a few reasons why you should be keeping your email subject lines short. Firstly, it will help grab the attention of subscribers who are scanning their inboxes. There’s just no need to include any superfluous words or details; just get straight to the point.

Take this subject line from an email newsletter I received from BoardwalkBuy as an example:

subject line boardwalkbuy email newsletter ecommerce too long

This subject line would have been much better if they made it more concise – “Save up to 95% on purses and handbags”, for example. This would have both drawn more attention to the most important part of their subject, and would have been more easy for readers to digest. There’s also no need to cram everything into the subject line – BoardwalkBuy could have saved details like ‘Stylish and Trendy’ and ‘Makes A Great Gift’ for the body of their email.

Secondly, keeping your subject lines short will help them to not get cut off.

email subject lines too long cut off

Although Gmail will allow your email subject line to be around 80 characters, we would not recommend trying to fit as much as you can before it’s cut off. Try keeping it to 50 characters or less to be safe, and remain engaging for subscribers.

This is especially important for your emails’ readability on mobile – 54% of marketing emails are opened on mobile devices. On my phone, email subject lines are cut off at around 30 characters, both on the in-built Mail app, as well as on Gmail’s own app.

apple ios mail app iphone email subject lines cut off
gmail mobile app email subject lines cut off

Basically, just keep your subject line short and sweet to avoid deterring subscribers and being cut off by display settings.

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Don’t be impersonal

A big mistake that plenty of email marketers make is that their emails read as very transactional, and consequently impersonal. Subscribers don’t want to just feel like a number, or that you just want to bombard them with products to buy.

However, something as simple as addressing your recipients by name will help them feel like you’re interested in providing them with a good customer service experience. In fact, personalized email subject lines result in a 22.2% increase in open rate.

optus promotional email newsletter personalization name

To make this strategy more effective, a good idea would be to use your personal name rather than your company name. This helps to add a much more personal touch to your marketing emails, making it more conversational and casual for your subscribers.

mahabis alice email newsletter personal name

While Mahabis has adopted this more personal strategy, they could still take this a step further and send out their newsletters with a more personal email address. Email addresses like ‘hello@[company]’, ‘info@[company name].com’, and especially ‘noreply@[company’ come off as very cold and impersonal.

Don’t be ambiguous

You might think it’s a good idea to be all cool and mysterious when it comes to email marketing. Tease your subscribers with the subject line to get them interested, and they’ll be sure to open your email, right? Wrong. Would you open this email based on the subject line?

cupshe email subject line ambiguous

Be upfront and let your subscribers know what you’re giving them, whether that be a special offer code, product recommendations or news about your products. It’s also a good opportunity to use a call to action. A call to action in the body of a marketing email can lead to a 371% increase in clicks and 1617% increase in conversions, so why not adopt this practice for the subject line of your emails as well?

barnes & noble call to action subject line

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Don’t be annoying

There are a few little marketing email pet peeves I have:


Stop shouting at your email lists. You’re trying to get subscribers to open your emails, and eventually click through to purchase something. But if you’re going to do this aggressively, it’s just not going to work.

If you’re trying to get your email in inboxes, all caps and salesy subject lines will at best land you in the promotions tab. At worst, they’ll send your email to the spam folder.

For more tips on how your subject line can impact your deliverability read: 7 Hacks to Improve Your E-Commerce Store’s Email Deliverability

boardwalkbuy email newsletter all caps
2. Overusing punctuation?!?!?!?!?!

Remember what I said earlier about keeping your subject line concise by excluding superfluous details? Well excessive punctuation is superfluous. Do you really need that many exclamation marks? No. I know you just want to convey your excitement, but one will do the trick.

buykud email newsletter overusing punctuation exclamation marks
3. Too many emojis

I love emojis as much as the next person. And using one or two in your email subject line is perfectly fine. But avoid using too many that it starts detracting from your content.

If you are going to use emojis, test out your email to ensure that your subject line is able to be read on different devices to avoid the dreaded blank square.

For more tips on using emojis in your headline, read our guide on Emoji Use in Email Subject Lines.

boardwalkbuy email newsletters subject lines emojis
4. #hashtags

A few months ago, it might have been okay to use hashtags in your email subject line. But if you were to use them now, you risk making your store appear a bit dated. So please no more #squadgoals, #blessed or #fitspo.

email newsletter teeturtle hashtags squadgoals
5. Annoying slang

Similarly, using slang might make you seem a little outdated to your younger subscribers. But you also might alienate your older recipients, who may be unfamiliar with your use of jargon. Before using ‘lit’ or ‘shook’, make sure the slang resonates with your target audience.

culture kings email newsletter subject line slang
6. Speling misteaks

This might seem obvious, but make sure to double (or even triple) check the spelling and grammar of your subject lines. Having a tonne of spelling errors and grammatical errors not only makes you look sketchy and unprofessional, but is a surefire way to have your subscribers mark you as spam, or get your emails picked up by spam filters.

To read more of our tips to avoid being picked up by spam filters, read here: A Quick eCommerce Marketing Guide to Avoid Spam Filters.


Your email subject lines are the most important part of your marketing emails. Before subscribers even read your brilliant content and click through to your e-commerce store, your subject line is what will influence your readers to either open or scroll past your email. While we don’t really want to give you a formula to work from, we can give you some things to avoid doing to ensure that your subject lines are read by your email list.

If you’re looking for additional help, there are email subject line tools available online that are designed to judge the quality of your subject line.

By following the tips mentioned, your subject line will be good – but remember that it’s your brand and personality that will make your subject line GREAT!

Looking for more specific guides on writing subject lines?

We have create lists of great examples that you can use for the following events:

We also have lists for certain types of emails, including:

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