Email Subject Lines Common Mistakes

Are you aware that you have the ability to enter approximately 255 characters in the subject line with no spaces for outlook.  For Google’s Gmail you can enter 220 characters with no spaces.  Now I don’t think any good marketing person in today’s right mind would ever do this, but hey ya never know.  I recently had an email conversation with a very good client.  He emailed over four subject line choices to our service department for upcoming email broadcasts.  This conversation prompted me to share our experiences and a few common mistakes when writing content for a good subject line.  I would think maybe fifty characters total would be used.

Here are the four most common subject line mistakes that can trigger a spam filter to block your email: 

  1. Punctuation or symbols.  Content filters count any punctuation, particularly $, #, ! and ?, as spam indicators. Also, don’t use punctuation marks to disguise sensitive or trigger words in subject lines and body copy. That’s a certain spam giveaway.
  2. Calls to action. Content filters that assign points for various infractions or questionable phrasings consider any action verb to be “aggressive” language. The most common verbs in spam subject lines are get, open, download, buy, save, take, win, make, and respond. 
  3. Pronouns. Words like you, your, I, my, our, and we seem relatively benign and friendly – but they will trigger most spam filters, especially if used as the first word in a subject line.
  4. The “F” words.  “F” as in free, that is.  Business-class anti-spam appliances often filter out any message with this word – while consumer-grade filters may let it through. There are other “F” words that can trigger spam filters, including financial, freedom, for and friend.


Fifty characters could be all that stands between you and success in your next email campaign. Fifty characters is all the space you have in a typical email subject line to catch a reader’s eye and entice them to open your email to take the action you want.  How could something so small make or break an email marketing campaign’s success? Because many recipients use the email subject line as a filter to decide whether to open or delete an email.  Email subject lines are tough to create, but very important. A good one can get your email opened in a second, while a poor one could spell disaster in the trash or junk folder in a half a second.


If you want to write the best email subject line, pick up any newspaper or magazine. When watching the news tonight pay attention to the scrolling news at the footer of the TV screen and you’ll see nothing, but great subject lines.  The headline usually highlights a story’s most important fact in a limited space. A subject line, in turn, should clearly state what your reader can expect from your email message, what’s in it for them or what action step you want them to take as a result of the email. However, there isn’t enough space to do all of them all the time. Again look at the newspaper, magazine and TV news headlines to see how it interplays with the story.

Measuring Success

Look at the subjects associated with the highest number of conversions, such as registrations, submissions, phone calls, clicks to view newsletter articles, sales or downloads. If you drill down into your web analytics, you might find some anomalies, such as an email with a relatively low open rate, but a high sales-per-order rate or submissions. That could mean something in the subject line strongly appealed to a narrow segment of your email list and could point the way to a more lucrative segmentation. Remember, your end goal is not necessarily high open rates, but to have email subscribers take a specific action. Focus on your end goal.

Do you have a Deadline the Tax man does

Set a deadline: “Order by midnight tonight;” may not work for a insurance professional, but you get the idea here. Use urgency and deadlines as part of a planned series of emails as well. For example on Monday incorporate “5 Days Left.” and then on Thursday follow it with “Only 24 Hours. I constantly receive emails from Carriers, MGAs and wholesalers who are offering prizes and trips for the a certain number of bound accounts or submissions.  A retail agency can incorporate a number of different contests from referrals; gift cards and vacation give always.

Subject lines need to pass Must-Open & Must-Read test?

The days when people opened everything that landed in their inboxes are gone. Now, you have to intrigue them. Appeal to their need for information, to be an insider “in the know.” If you have created a conversation with your readers, a reference to it in your subject will intrigue them into opening your email to see the next installment. Run a simple test on yourself and others on your team – does the email subject line pass these two tests? The must-read test. If a subscriber doesn’t open the email they will feel like they are out of the loop and may have missed an offer that they will regret not taking advantage of.  The unbulk bulk-folder test. Simply, if for some reason your email goes into the bulk folder, does the combination of from and subject line wording inspire trust and intrigue to get the recipient to move it into their inboxes? Conclusion: Lots to Learn, Lots at Stake Right? This seems like a lot of fuss over 50 small characters. But those 50 characters may have the greatest impact on your email marketing campaigns’ success. It pays to get them right.