5 common email subject line mistakes you need to avoid
Written by
Kanika Sreen
Kanika Sreen

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5 common email subject line mistakes you need to avoid

Published : May 25, 2023

What one of the greatest musicians says about life is true in the world of email marketing as well.

The hip-hop legend Nas once rapped, “Get it right, you only have one first chance/To make one first impression that lasts a lifetime.”

In the age of Instagram filters and goldfish-level attention spans, first impressions are everything. And, often, they can go terribly wrong.

In email marketing, the subject line makes the first impression. We’ve written about creating email subject lines that work, but now it’s time to look at the flip side.

When do email subject lines go bad? When do they make the recipient raise their eyebrows and click “delete” or just ignore and pass over to the next mail?

In this article, we look at five common subject line mistakes you should avoid if you want to give your emails the best possible chance of being opened. Avoiding these mistakes may not guarantee opens (nothing in the world can); however, it will prevent losing customers for entirely avoidable reasons.

Using ALL CAPS and too many punctuations

Would you open an email with this subject line: 50% OFF ALL YOUR PURCHASES FOR THE NEXT 48 HOURS!!!!!!!?

The promised reward is excellent, but the proclamation is loud, desperate, and overpoweringly sales-y. Yes, every brand’s goal is to sell, but can we be a little more elegant about it?

Subject lines like this almost always make users ignore or delete the email. They can even be marked as spam, hurting your brand credibility and reputation with mailbox service providers (MSPs) like Gmail, Yahoo! Mail, and others.

Excessive capitalization qualifies as screaming. SO, DO NOT TYPE IN ALL CAPS UNLESS YOU WANT TO SCARE CUSTOMERS AWAY. If your product/service is good enough, you don’t need to scream your message in your subject line. That’s what advertising is for.

Similarly, too much punctuation or even special characters (such as * % & # and ^) can trigger spam filters (on top of looking ridiculously amateurish). So, they are best used sparingly or avoided altogether.

You could, however, capitalize a single word in a subject line and make meticulous use of a single punctuation mark in subject lines. It will help you make your point without appearing far too eager.

Quick Note: Don’t use too many emojis to appeal to Gen Z, either. Unless you’re doing it because it fits the subject line organically, it will come off as try-hard and put-on. Pass.

Using words that activate spam filters

Certain words trigger spam filters even if the subject line has no intention of spamming its recipients. These words, phrases, and symbols – “$$$,” “100% free,” “cash off,” “cheap,” “weight loss,” and “serious cash” as examples – should be avoided entirely.

Apart from being caught by spam filters, these will cause recipients to think your email is spam; and the outcome of either scenario is equally disastrous for you as a marketer.

You can Google comprehensive lists of these “spammy” words, so you’ll always know what to refrain from if you want to avoid the spam folder.

Not optimizing for mobile screens

Several studies and reports have shown that over 60% of emails get opened on mobile devices. Mobile screens are much smaller, so ensure that the subject line is entirely (or mostly) visible, even with limited real estate.

Additionally, symbols and special characters in your subject line that use html codes shouldn’t render as garbage when viewed on mobile devices. Yes, that happens quite often, and it is because of the incompatibility of the mobile device hardware-software configuration with the html code used for a symbol or special character.

With unrecognizable text or shapes in the subject line, the only people opening your emails might be bots or those who believe that ²aliens are communicating with them ?. Neither will help you meet your marketing goals.

Using subject lines that are either too long or too short

Nobody wants to read a novel in the subject line. The criteria “brief,” “pithy,” and “catchy” are your best friends. Keep your subject lines to the point.

In the mobile dominant world, the optimum subject line length with the highest open rates is 30-35 characters with spaces. Lines beyond 36 characters get automatically truncated and abruptly break the description (source: Netcore’s Email Benchmark Report: A study of 100 billion emails)

The subject line is to entice, not educate – save the details for the email body.

Conversely, don’t sublimate your subject line to a single word to keep things short. No one is opening or reading an email with a subject line that says “Important,” “Survey,” or “Urgent.” It is the very definition of lazy, generic, and uninteresting. It is also a great way to get your emails marked as spam.

Misleading content

Do not tread the gray area between truth and deceit just to get your emails opened. It will severely damage your brand credibility, cause you to lose users, and even be penalized/ blacklisted by email providers like Gmail and Yahoo! Mail.

Be absolutely transparent about what readers can expect from an email. Don’t use lines like “You might be in trouble…” or “You missed a 0% discount”.

Following up “You might be in trouble…” with something like “…because we’ve slashed our Christmas prices even further” might work once or twice, but it’s a gamble that can play out either way. Your customers have a lot of things to do, and they want direct communication so they can make choices fast.

A good subject line is a foot in the door

Let’s start with getting people to first open your emails.  Once they do, an interesting and relevant body copy can get them to act and click the CTAs.  Therefore taking the time and effort to craft a solid, targeted subject line always pays off in the long term. It helps you grab the most valuable commodity in all of marketing: the customer’s positive attention.

If you aren’t feeling super confident (yet) about creating subject lines that folks on your email list will love, why not let us give you a hand? We send over 20 billion emails a month on behalf of 6500+ businesses across 40 countries. Helping brands create great email campaigns is integral to our email products and services.

Connect with us, and let’s discuss how we can help you crush those email marketing goals every quarter!

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