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How to optimize your email subject lines for sales.

How to optimize your email subject lines for sales.

By 2025, more than half of the world’s population will be using email. That’s over four billion people! Email marketing is an easy choice for most businesses because it is affordable, easy to use, and incredibly effective – boasting an average return on investment (ROI) of $40 per dollar spent. And unlike direct mail, email marketing has no printing costs, links more easily to digital platforms, and is accessible from anywhere, at any time. The problem is, with a less-than-20% average open rate, four out of every five emails will never be opened by a consumer. With over 333 billion emails sent daily, many of which aren’t flagged as spam, consumers have understandably become selective about which they open. If you can’t grab their attention with a subject line, your budget for content and promotional offers won’t matter at all. The problem is, not everyone is clear on the best practices. In this blog, we’ll discuss how to improve open rates and avoid spam filters by writing effective email subject lines for sales.

Avoiding Spam Filters

Before a consumer gets a chance to read your subject line – a spam filter does. These algorithms are specific to the mailing platform and designed to prevent unwanted and/or malware-ridden emails from appearing in a user’s inbox. Consumers love spam filters because they keep their inboxes clean, but marketers find them difficult and frustrating to circumvent. First you optimize for spam filters, and then for clicks, but both require you to choose your words carefully when writing email subject lines for sales.

Here are some general themes to avoid in subject lines:


If you want to make it, don’t talk about it. Leave words and phrases like “cash back”, “profit”, and – worst of all “discounts” – for the inside of your email. No matter how well-intentioned you may be, it almost always comes across as either shady or tacky, and neither is good. Don’t cheapen your brand by leading with money talk.   

Desperate or Urgent Selling

Just because you’re optimizing email subject lines for sales, doesn’t mean you need to sell in the subject line. You want your content to do the selling. The subject is only a teaser. If you wish to imply that your offer is urgent, be sure to keep it subtle. Consumers do not respond well to being rushed or bombarded. Give them just enough information to click on the email, and then you can create urgency with a “limited-time offer” and call to action inside.

The word “Marketing”

Like we mentioned above, just because you are marketing, doesn’t mean you need to say that. No salesperson opens with the line “Hey, I want to sell you something,” even though that is indeed their end goal. Catch your audience’s attention with something interesting first.

Never use CAPS or Emojis

Notice that we said interesting, not obnoxious. Entirely uppercase words and sentences almost always come across as shouting – and no one wants to be yelled at by a marketer. Emoticons, on the other hand, seem out of place in the subject line of an email and can make your message appear frivolous. You can use emojis when targeting a very specific market that you know will respond well – but for the most part – we advise against them.

Personalize Your Emails

It may seem strange to call someone by their first name when you don’t know them personally, but 71% of consumers expect email personalization. Personalized emails allow you to establish a sense of familiarity and make consumers more likely to click on your subject line. So, if you have access to the information, make sure to use it to your benefit. Addressing a consumer by their first name when writing email subject lines for sales is a great way to improve your open rates. 

Link to It, Don’t Attach It

Email attachments can also trigger spam filters, especially when sent to a large number of new recipients. If an algorithm can’t verify the source of the content, which occurs frequently, the email is sent straight to spam. To mitigate this, link to a landing page or website where the attachment can be found, instead of attaching it. Mailing platforms that already have established credibility can help you to get around this, but always send test emails internally before sending to your list. Typically, real spam emails contain attachments. So, either send fewer emails to established clients, or link to it – don’t attach it.

Build Mailing List Credibility

When you are sending your first mailers, don’t bite off more than you can chew. Large lists tend to be broad and therefore include lots of non-targeted recipients. If your content doesn’t match up well, the algorithms will catch on and flag your emails as spam. The bigger the list, the more time or money you most likely invested to secure it. Don’t waste that on mailers that never reach their destination. Instead, select a small list of the targets most relevant to your content. From there, you can increase your mailing list incrementally to widen the reach. Be sure to scan through your mailing lists and remove any unwanted contacts as often as possible, also.

How to Simplify the Process

Looking for the easiest way to combine all these best practices consistently and effectively? Talk to the experts! Strategic Marketing is a full-service agency with three decades of experience crafting email subject lines for sales. With one phone call, our professional team can evaluate your goals and provide an optimized email marketing strategy for success. Let our experts get your message past the filters and into inboxes with ease. Furthermore, we can help you to achieve a higher click rate and more conversions with expertise in copywriting, graphic design, landing page development, SEO, and so much more! Make the right move and contact Strategic Marketing today to optimize your email marketing.