Words to avoid in Email Marketing subject lines

The subject line of a marketing email is arguably the most important part of the whole email. It acts as the gatekeeper to your content, determining who will open it and who will ignore it.

The most effective email subject lines tend to be short and descriptive, giving the reader good reasons to explore your message further. Whereas ‘cheesy’ subject lines are a turn-off for most readers.

Subject lines that explains the benefits the reader will get from the email are more successful than those which instruct the reader what to do. Readers like “what’s in it for me” information.

A recent article from eConsultancy looked at the positive and negative impact of certain words in subject lines, and had some great tips. It also looked at whether you should use emojis or graphic symbols.

Here’s some other advice on improving email marketing open rates:

– Avoid words like “free”, “help”, “reminder”, per cent off”. They may avoid the spam filter but all have been shown to negatively affect open rates.

– Use email personalisation with care. Research shows that overall it has minimal impact on open rates if done well, but negative impact if the data is inaccurate or incomplete.

– Email newsletters – the same rules apply. Change the title with every newsletter – give people a reason to open it this time. They need to understand there is something new for them inside. Otherwise open rates of newsletters tend to decline over time.

– Subject line length – keep it concise and to a single message. Around 50 characters appears to be the sweet spot.

– Think about the ‘pre-header’ content – many email clients will display the first few words of the email content together with the subject line in the InBox. So similar rules should apply to that as well.

– The ‘From:’ line information. This can have a major influence on open rates. Consistency can build trust over time with readers. It therefore adds credibility to the subject line itself.


Probably the simplest and best guidance is to think about what you would like if you were the recipient!