Email subject lines are known as the make-it or break-it part of email marketing. Subject line acts as the first interaction with a new and brand marketing campaign. It should deliver and value the brand’s personality and enable the visitors to open and read email.

Most of the small businesses have little concentration in this factor which drives customer engagement. No one wants to make such a mistake in marketing.

Not taking care of subject line falls to a drawback of bad results and downgrades the reputation and pushes the emails to the spam folder. It is stated that- the more time spent or reported as spam is proportionate to less deliverable in getting future emails in return having a drastic effect on the campaign ROI.

Never fall down, take measurable steps in clearing the subject line mistakes. Be aware of the pitfalls and get the ability to prevent them.

A poor and wordy email subject line, unnecessary symbols, are a few mistakes to avoid while writing a proper subject line. These may confuse the reader and decrease Email relevance. These may cause differing, ignoring, and deleting of email without opening.

Below are the 10 email subject line mistakes to avoid:

  1. Using Spammy words

When anything is seen unusual, people make those emails as spam or even delete them. Even in case if it includes anything legitimate. Avoid using spam words like Money, Free, Win, Bonus, Sign-Up!, Now!, Limited, Offer, Join, Order, Cure, Percent-off, Deal, Gift, Millions, One Time, Increase sales, Home-made, Obligation, Limited-time-offer, and No investment. These may sometimes attract users but neither of the time reduces the interest and make users annoyed of them.

These may not be helpful in reaching the intended subscribers or recipients. Apart from the given list, there are many spammy words that may not be used. Having a negative reputation leads to issues in email deliverability and lower search engine ranking.


  1. One Word Subject Line

Never add a single word subject line. It may be viewed as spam and even makes users delete. The one-word subject line may include Important, Survey, Hi, and all these may spam as it is shown as a concern of content professionalism. So it is suggested not to use one-word subject line emails to the users. Follow some protocols and write subject lines that are relevant and effective.


  1. Too many punctuations and ALL CAPS

When an email with the subject line is received with CAPITAL letters and symbols, there are chances in sending email to spam or ignore or delete. Excess of punctuations and CAPS letters may scare the subscribers and decreases the open rates. It intimates something is yelling and that have a negative impact on the email performance. So it is suggested to reduce the using of CAPS and punctuations.

Sparingly, it is suggested to use phrases like Act Now, Free that improve open rates with a diluting chance of making the email as spam.

Special characters like %, &, #, *, ^ are known to trigger filters of spam and these should be used with a special caution in any field. Question marks, periods, exclamation points lead to more open rates.

Around 2-4% of emails have an exclamation in its subject line that ends with a full stop or a period. The open rate is 1-20% higher than the usual one. This value may change with respect to the industry and audience. Try implementing these in many fields of marketing and have an idea on which punctuation or question lead to higher open rates. Don’t mix exclamation, period, and question mark in the subject line.


  1. Writing lengthy description

When an email is viewed on the desktop, there is a chance of viewing 60 characters at a time. While on a mobile screen only 25-30 characters can be viewed. Presently, 50% of emails are only viewed or read on smartphones. With the experience in email subject writing, experts have given a clarification that- if the email subject line is not impressive and include a lengthy description, the visitor or subscriber cannot resist on reading the entire email. So try adding important points in the starting of the email subject line keeping in mind the end users or readers.


  1. Misusing emojis

Emojis can literally increase open rate, where only a few applications are limited and have to be employed in the right way.

If the business products or services are conservative, using smiley symbols may not be helpful in matching the brand image and identity.

These emojis are rendered across many platforms. Instead, use a few characters which attract many viewers. They work in rare applications so use them accordingly that match the brand representation.


  1. Not intimating Urgency

For sharing a piece of information in the subject line is through explaining the emergency in the subject line. Enable writing lines requesting the urgency. It should have the capability of responding to the message quickly.

Add timeline in the Email subject line whenever needed. Instead of regular language add some exciting and specific keywords that result in high chances of opening the email by the visitor or subscriber.


  1. Using end sentences in the starting lines

If a question or thought is asked in the starting of the email body, the reader tries to go deeper into the email to know more in detail about it. It resembles and captures the clarity and the visitor’s time. But in case of the subject line, projecting questions is not a correct point of approach. It is recommended to add instant- message, in-person chat, call-to-action which acts as a better medium for posing a question.


  1.  Grammar errors or Spelling mistakes

Subject lines that include misplaced punctuation, typos, misspelled words may look unprofessional and may lessen the open rates. Emails are a source of establishing a brand and stands as a medium of exchanging information. Subject lines with syntax errors, spelling mistakes can address an absent and bad impression that undermine the ability to build trust with the subscribers.

For optimizing this scenario, practice reviewing of emails for spelling and grammar prior sending it. No one likes to open and read the entire email if the email subject line is irrelevant and has blunder mistakes. Copy editing can reduce these errors.


  1. Ignoring preheader text

Many of the marketers don’t even know about it. Yet, the preview, a preheader misleads the open rate. Preview after creating an email that appears in the customer’s inbox after the subject line.

Differed with the personal email, business emails include a subject line that normally has browser instructions or image alt text. Most of the ESPs help in adding a minimum of 35-90 characters to attract recipients eye and supplement the subject line for having higher open rates.


  1. Mobile Optimization

Presently, there are 81% of people who usually rely on mobile phones for checking their emails including the subject line. Hence making the subject line and the entire email optimized to the mobile is mandatory. Otherwise, there is a chance of missing the email or ignoring it as spam.

Check responsiveness and make sure the subject line matter is not translated into random numbers or characters when opened in a mobile. This can be reduced by previewing the email across many browsers and channels before sending. Duplication cannot be encouraged. Unknown characters and text will make spell disaster on a whole.



The subject line is similar to a headline of an article or a letter. It should definitely capture the reader’s attention and provide key information, convey the actual importance, on the whole it should highlight the deadlines.

By following and avoiding the above mistakes greatly, anyone can improve the ability to exchange messages efficiently and effectively enabling to read the entire message.