6 Mistakes to Avoid on Email Subject Lines

by Daniel in — 32 Comments — Updated — Reading Time: 3 minutes

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If you are a blogger, website owner or online worker, you probably need to contact people via email all the time. On some occasions you will also be the one starting the conversation and looking for a reply. For example, you might want to offer a guest article for a particular blog, or you might want to propose a business partnership to someone. Unless you craft your email messages smartly, though, there are good chances that the other person won’t even read them. Spam filters are the first obstacle, but even if your message goes though the other person might just delete it.

The subject line is probably the most important part of your message, and in this post I wanted to cover six mistakes that I see people making:

1. Creating one word subject lines

Have you ever received an email with the subject line “Hi”? If you have, you know how annoying it is. One word subject lines are terrible because they fail to communicate what the email is about, where it is coming from and the like (more on that later). Additionally, they might also reveal laziness or carelessness from the sender’s part, which might lead the receiver to ignore the email.

2. Making requests

People want to receive, not to give. If your subject line makes a request right away, the receiver will be less likely to open it. Examples include link exchange requests, voting requests and so on. A better approach to get the conversation going is to start by offering something.

3. Using spammy keywords

Using spammy keywords in your subject line is a no-no. Even if you get lucky and the spam filter does not block your message, there are good chances that the receiver will tag your message as spam as soon as he reads the subject line. Here is a short list of words to give you an idea of what should be avoided:

  • free
  • money
  • win
  • degree
  • gift
  • deal
  • sign-up
  • survey

4. Begging for attention

Using “Please Read This” as your subject line will not help convincing the receiver to open your email. Quite the opposite. The same is true for using words like “urgent,” “important” and similar.

5. Making it sound too good to be true

Real business or joint venture opportunities usually come from people you already have a relationship with. If you are going to email someone for the first time, therefore, avoiding using these terms, else you might be seen as a scammer.

6. Making it look like an automated message

If your subject like looks like an automated message from a website or online service, well, people will assume it indeed is. Just take a look at the automated messages you receive and avoid crafting your subject lines in the same fashion. One example is the “Invitation to…” subject line. Usually those come from social networks, and people tend to ignore them.

By now you might be asking yourself: “OK I understand the mistakes I need to avoid, but how should I craft a good subject line then?” In my opinion a good email subject line should have two elements: a relevancy hook (i.e., a keyword that will assure the receiver that the email message is indeed for him, like his name or the name of his website) and a brief description of the content of the email (because even if the receiver knows your message is a legitimate one, he might not read it immediately or at all unless he knows what it is about).

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32 thoughts on “6 Mistakes to Avoid on Email Subject Lines”

  1. The subject line in an email is like the headline in a letter. If it grabs readers, wonderful. If it turns them away, not so wonderful!

    It really does deserve as much time and thought as the message below.

    I think one of the biggest “sins” is to be misleading. There are few things so annoying as to open an email on the promise it contains, only to find that you won’t get the answer unless you send $39.95!

  2. This is a very informative post and lots of key information is presented in it. Leaving out words that are considered to be “spammy” is key. Sometimes those words leave the impression the person opening it is still going to be hit up for money or going to be led to a site in which they will be solicited.

    A lot of the information in this article could be utilized for job searching and networking as well. During my professional career, I have interned or worked for people who have complained and refused to open e-mails that contain one word subject lines, subjects that beg for attention, or ones that look like an automated message. With the amount of e-mails some professionals and high executives receive per day, skipping over ones that come across as Spam or money solicitations becomes a lot easier if the subject lines are not clear. Sending out the same e-mail to multiple people (e.g. sending it out the same e-mail to 30 people) will often end up in Spam folders and will never be opened.

  3. Great list, two more things I’d add…

    Someone asked how long your subject lines should be–somewhere (maybe Marketing Sherpa?) I know I picked up 35 characters is the max to shoot for

    With all the preview pane readers these days the first two words of your subject line have become super important. So try to avoid starting with boring words like “the,” etc and make sure yours gets off to a strong start


  4. It’s amazing that this needs to be written out. It would also be great to send to all the people who need the “clue,” but that would be spammy now wouldn’t it? I agree with all the suggestions you made as those are usually the ones that automatically hit my radar when going through email. I get quite a bit, so after a while I have gotten down a pretty good system of what to look at immediately (and hopefully quickly), what to immediately delete without opening and reading, and what to hold onto. A really bad faux pas is to have nothing at all in the Subject line. Bad, bad, bad.

    Last thing, if I made it past the subject line and opened the email, keep the information to the point of the subject line, concise, and with the specific information I need to get back to you. I work with one person who completely inundates her message with so much “related” stuff, by the end I don’t even know they are desiring a response from me. I have a lot of work and a lot more emails to get through. If you haven’t stated what you need early, I have moved on. Better yet, start with the request and then elaborate. I am more apt to read what you have to say for clarification in order to respond to your request.

    Nicely done, with great information.

  5. What I find to be the worse subject line is when there isn’t even any subject typed in. That to me ranks right up there in laziness and unimagination!

  6. Nice list of email tips! Most of emailers are really not aware of those you have mentioned.So it is a must read to everyone serious on their business

  7. Thank you for this great list.

    I was making the mistakes #2, #4 and #5. But I did not realise that these three points could be mistake. I now agree with your arguments.

  8. I avoid putting the name in the subject line, because just about the only place I ever see that is in “form” messages that want to offset their “spammy” call-to-action.

    I tend to use good ol’ fashioned statement of the subect, as though it were the “RE:” on a printed memo. If it’s relevant and personal, it will be recognized.

  9. Like many of the readers who have already commented, I always have a hard time deciding on a subject line.

    Is it bad to have long detailed subject lines?

    @vamsi – I am also curious about caps. Chris brogan mentioned he likes some caps in a email.

    What do youthink about caps Daniel?

  10. You are correct Daniel. Most of the time, we can easily make out if a mail is sent from a person or is part of a spam campaign. But with a very few campaigns, I have taken the trouble to open, click the link and even complete a survey. But they are very few really.


  11. I used to think that email subject lines were basic, and took it for granted that everyone knew how to use them. Reading this has made me realise that it’s not so basic after all and that people do make mistakes in labeling their emails.

    I’ll make sure I check each subject before ‘sending’ from now on.

  12. When it comes to emailing to readers, it’s always a bit ‘scary’ and I must admit, some examples mentioned here are not my picks either. I did a couple of so called ‘mistakes’ before, but I think the real one made is not to think thoroughly on the subject line. I figured as long the content is sincere, it’ll make up for it. Perhaps first impression is not the content, but the subject line itself — especially those who never read your site, have no idea who you are.

    Something to think about. Thanks Daniel.

    Social/Blogging Tracker

  13. i always try to keep subject line for email as simple as possible.it is good practise to keep subject line in such a way that reader get idea what in the email

  14. Daniel,

    Thanks for coming back and for the clarification.

    I “autorespond” 4 advice type emails for every ‘sales’ type.

    I now need to go through and check they all meet your guidelines!


  15. Email titles have a fine line. You want something “catchy” but not “spammy”… that’s a thin middle ground.

    As a general rule, if you can spell out the benefits of the call to action, then that’s a good start.

  16. I seriously dislike subject lines. I sit there stumped all the time, unsure of what to say, and end up writing some stupid line like, “Hey, how’s it going?” FAIL

  17. Thanks Daniel, great advice. Many of us are guilty of the ‘spammy’ keywords use/misuse and we also believe the best way to get someone’s attention is by using “please respond’ and ‘Urgent’ to get their attention. It’s good to learn why they wont respond 🙂

  18. #1 – Can’t agree more. I used to work with a guy who just used the word ‘here’ as the subject for every e-mail he sent. Trying to find certain ones weeks or months later was a major pain.

  19. @Andrew, btw my last point was not against autoresponders. You can make your automated messages very relevant to your subscribers, for example by including their name and a description of the content on your email message.

  20. @Andrew, that is always a good idea, as long as your messages will help to build a relationship with your subscribers (as opposed to spamming the heck out of them).

  21. Daniel

    Thanks for coming back to me.

    I was thinking more around the setting up of x number of months of autoresponders when someone opts in for a giveaway or product.


  22. I also heard that you should avoid using the word ‘specialist’ in the header because the spam detector will see the word ‘cialis’ in there.

  23. @Andrew, I believe email marketing is a must for anyone doing business online. That does not mean you should reply to every email sent to you with an auto-responder though.

  24. Good stuff!

    Must admit I have used some of those spammy keywords before.

    What is confusing is some gurus say don’ use autoresponders, some say do. Daniel, what’s your take?




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