Branded e-newsletters are as vital for your business today as they were decades ago, when email first became the ubiquitous messaging system.
With 4 billion email users worldwide  and a return on investment (ROI) of $36  for every $1 spent, suffice it to say businesses can’t ignore email marketing.
But with the ever-changing digital landscape, modern branded e-newsletters have undergone drastic changes — and continue to evolve. What once was a nice-to-have hub-and-spoke-focused blast with multiple links out to your products or services has morphed into something else entirely.
Mobile has become more prevalent in content consumption (totaling more than 50%  of all internet users); brands have had to shift how they present their content with a mobile reading experience top of mind. This has led to the birth of companies like The Skimm and The Hustle, whose primary focus and output are e-newsletter — that’s how lucrative it has become.
So how do you strike the right balance of promoting your business without coming across as too sales-y in this saturated market? Here are some best practices for using email to keep your customers engaged.
1. Respect Your Customers’ Time and Interest
The frequency at which you send e-newsletters will depend on your industry and consumer base. You know your customers better than anyone else — how often do they really need to hear from you? A 2015 survey conducted by Marketing Sherpa  found that just under 90% of people prefer monthly emails, while more than 60% prefer weekly.
The last thing you want to do is start sending daily emails that all say the same thing — your newsletter copy should reflect the interests of your subscribers, so if you have something new, relevant and timely to say daily, go for it! If not, consider scaling back so as to not cause a nosedive in subscribers. And remember, once someone unsubscribes, they’re gone — you must remove them from your list to avoid any penalties.
2. Offer Something of Value
Tying into the above point, your newsletters should be 90% educational and 10% promotional. While your overall goal might be to sell more, building up trust and developing a relationship with your audience come first.
If you’re a subject matter expert, consider giving your top tips on a topic. Offer a free trial of your service, a percentage off your product or a free downloadable with key information. It’s really a value exchange — your brand gives, the consumer recognizes and opens your emails more often, which increases the likelihood of a sale.
3. Test, Learn, Evolve
Your brand should try different iterations of content, offers or calls to action (CTAs ) to see what resonates best with your audience and to help target them more efficiently in the future. In fact, brands that A/B test typically have a higher ROI than those that don’t. 
And it couldn’t be easier: Most email marketing platforms have A/B testing tools that allow you to play around with your subject line, copy, design and even the time of day you reach people. Ensure you’re monitoring the open rate, click-through rate and any transactions that come from your email blasts to see which messaging is working.
4. Optimize for Mobile
As previously mentioned, the majority of online activity takes place on mobile devices today. This means your newsletters shouldn’t just look and read well from a desktop but should also be functional on a smaller mobile screen, too. Research from Mailchimp  shows that mobile-responsive designs can increase audience engagement with e-newsletters.
Again, the platform where you host your emails will likely have a mobile optimization tool to help with this, but you can also use larger font size, a single column layout and design bigger buttons for easy selection. Ensure any images you use are sized correctly for mobile, too. You can check how your newsletter will look on mobile before sending with most email builders.
5. Keep It Simple
Perhaps the most effective tactic of them all — simplicity.
We’re talking one CTA. Don’t ask your audience to do too much. Be clear and concise in exactly what you want them to do when they open your email. Similarly, keep the language simple. Having a clear goal for each campaign you send out will help with this.
The design should be minimal too — white space is crucial to reduce that “jumble of words” effect and it makes your content easier to view on mobile. Plus, many people don’t have images enabled when receiving email, so the fewer you have, the better in many cases. When you do include images, ensure each one has alternative text that shows up if the image is blocked.
For help on jumpstarting your outreach, get in touch! We have an expert team of content marketers that can support your brand strategy!
Kelly Meehan Brown is editor and social media manager of Millie Magazine, a Foundry 360 brand. She’s also and an Irish expat who has been covering all things at the intersection of money and fun for the past five years. She currently lives in New York City with her husband and one-eyed black cat, Thackery.