Subject Line: Do’s and Dont’s to make your email land in the inbox

This is the first post from a series of email campaign deliverability posts by the Moosend team to help fellow marketers improve campaign performance by optmising key elements in newsletters and other email marketing communications.

Your efforts can be a waste of time and money if certain criteria flag your email or newsletter to ISPs, Email providers, spam filters and others. We aim to provide the best possible advice to get your email campaigns delivered to your subscribers’ inbox.

Let’s start with the first of our series, with the most important of touchpoint with your subscribers, your Subject Line…

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How To Craft a Subject Line

Subject line is one of the most important factors that can influence upwards or downwards your open rates. Every time someone reads your subject line makes a decision: “Should I open this email or not?”. It is the moment of truth! Hence, you need to be very careful when choosing a subject line. It is very likely that you’ll end up spending the same time you spent designing the newsletter.

Things to avoid:

Avoid spammy words like, “free”,  “help”, “urgent”, “action required”, “Buy now”, “Cash”, “Earn”, “Millions”, “money”, “$”, “percent off”. These words may appear very attractive and have you thinking that your newsletter will be irresistible. However, spam filters will detect them and, most probably, will place your newsletter into the junk folder.

Avoid full words in capital letters. We know and we understand that you are excited and you want to shout out loud to the whole universe about your new offer, or announcement, but the truth is that you don’t have to use words in capital. When writing for the web, screaming equals putting all words in Caps. The moment you “shout”, spam filters will stop you and no-one will listen or read your amazing newsletter. You just have to think better and smarter ways to attract your subscribers’ attention.

Avoid using many punctuation marks. Like words in capital letters, you should avoid the usage of many punctuation marks. One is enough, your readers will understand how excited you are with just one exclamation mark (!) and spam filters will stay on hibernation.

Don’t use “Re:” or “Fwd:” It is very important to understand that you do not want to trick your subscribers by making them think that you have an opened discussion with them or you are forwarding them something that they have asked you to do so. This is a trend that most spammers are using and of course most of the spam filters already know that.

Things to do:

Now, that we have discussed what to avoid, in order to have better chances to hit your subscribers’ inbox, it’s time to move on to some tips that can boost your open rates and make your audience open your newsletter.

Make it personal. Readers really like to feel that you know and care about them. So, use personalisation tags (, to include your recipient’s name or some personal information in the subject line. An example might be:

Joe, our new collection just arrived! Take a look
Joe, 56 points are waiting till the end of week

Keep it short, not more than 50 characters

Keep it relevant with the content. As mentioned above, you should never trick your readers, because you will lose them and they will never come back. There are probably many competitors out there waiting for you to make a mistake so that they win over your subscriber. Therefore, always keep your subject line relevant with the content of your newsletter and of course cohesive with your website. Offering promises that cannot be fulfilled, just to make the subscribers open your newsletter, leads nowhere. Even if you win this battle, the next one will be played with a losing hand: how to make your audience click on your links!

Ask questions. Your subscribers feel that you really care about their opinion, that you will take it under consideration and that they “need” to engage by giving you an answer.
Set deadlines. Limited offers in terms of time or quantity on your website, can be a very good leverage for your subject line, too. Keeping in mind that we need to show urgency and in the same time avoid words like “urgent” or “buy now” (they are spammy as we mentioned above), you need to be creative and express your urgency within the subject line.

Use emoticons. You can copy the desired symbols, e.g. ☂ ☁ ✈, and then paste them directly into the subject line.

A/B split testing. Test. Trial and error. Measure your results. Analyse. And start again from the beginning. The meaning of A/B split testing is to identify what triggers a specific audience to open the email A instead of another one, that we can call B.

In 10 seconds: Subject line is the first shot you‘ve got in order to get your audience’s attention. Needs to be catchy and smart. Having said that, email subject lines for sales that include words like “free”, “urgent”, “buy now”,  are identified as spam emails and end up in the junk folder. Writing a subject line is an art. It’s like walking on your tiptoes. Be cohesive with your content, take your vitamins and put your helmet on.

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