A Marketer's Guide to Improving Email Deliverability

Are your efforts falling foul of the spam filter? If so, you're not alone.


Savvy marketers spend countless hours building email newsletter strategies and crafting compelling content to engage their target audiences, but they don't always think about what happens once they've clicked 'send'. With well over half of all emails getting flagged as spam, it shouldn't come as much of a surprise that deliverability is becoming an increasing concern among email marketing teams.


Despite deliverability issues and the poor reputation that email marketing has among certain circles, the medium does still offer the highest return on investment of any form of marketing. A successful mailing campaign should prioritize deliverability by taking the steps necessary to ensure that the right content gets to the right people at the right time. That means building a quality mailing list and crafting irresistible content as part of a long-term, goal-driven approach to success.


It's also important to have a clear definition of what deliverability is. If you're thinking only about avoiding the spam filter, then you're taking the wrong approach. The goal of any email newsletter or sales letter is ultimately to convert, so that means getting in front of the right people and not trying to manipulate the spam filters. After all, having people manually flag your content as spam will only get you blacklisted, and is even worse than having your content ignored altogether. 


Avoiding the Spam Filters Isn't Difficult


How do you avoid your emails getting flagged as spam? The simple answer is to avoid sending spam in the first place! Nonetheless, there's a bit more to the process than that. Even if your content emphatically isn't spam, it might end up being manually flagged as such if it's ending up in the inboxes of people who aren't interested in your company or what it's selling.


Email content should always be relevant to its target audience. That means building up an opt-in mailing list consisting of engaged subscribers who actually look forward to hearing from you. This is also a legal requirement as per the CAN-SPAM act of 2003, and violation of the law can lead to enormous fines. In the US, the law sets the following minimum standards:


•   A physical address must be included in all email correspondence

•   Deceptive subject lines, headers and reply addresses must be avoided

•   All email newsletters must include a working unsubscribe link



The above rules should be commonsense to any responsible and ethical marketer, but there's a lot more to keeping your email above board than meeting these minimal legal requirements. You'll also need to understand how spam filters and email blacklists work to craft quality content that isn't going to get manually flagged as soon as it gets past the automated controls.


Spam filters largely rely on two things - email blacklists and keyword detection. Blacklists are basically vast databases of offending email addresses that have been flagged as spam too many times in the past. Email service providers, such as Gmail and Hotmail, partly rely on these for identifying spam. If your company's mailing addresses happens to be on one of these blacklists, then you'll most likely need to hire a reputation management agency to help you improve deliverability.


Spam filters also rely on detecting spam trigger words. After all, most spam emails are sent from brand new addresses, with spammers changing their addresses all the time to avoid blacklists cracking down on their operations. Spam trigger words mostly apply to the subject line. Common triggers include words and phrases that read like overused sales pitches, focus excessively on monetary value, include weak calls to action or use of capital letters or exclamation marks. 


Cleaning Up Your Mailing Lists


The first step in building a sustainable email marketing strategy is to build a quality mailing list. There are no shortcuts to this process, and building a valuable list can take months or even years. Nonetheless, it will eventually grow to become one of your business's most valuable assets. By contrast, buying mailing lists or adopting an aggressive list-building strategy is sure to get your emails flagged.


It cannot be stressed enough that content relevancy is a key driver in deliverability. Spam comes in many different flavors, with over half of it pertaining to industries such as health, personal finance, replica products and adult content. If your company operates in an industry that sends out a lot of spam, then you'll have to pay even closer attention to content relevancy. After all, not many people are interested in 'genuine imitation Rolexes' or 'miracle cures for snoring'.


Attracting the right prospects requires targeting your advertising to a clearly defined audience. You'll need to work hard to get people to subscribe in the first place, and that requires building authority and inspiring engagement through impeccable web copy, blog content and social media posts. Instead of gating premium content behind compulsory sign-ups, you should strive to build trust and create an irresistible value proposition that will have people expressly giving you their permission to send them content by email.


Always ensure your sign-up links and forms are clearly visible without being intrusive or disruptive. Never bombard your website visitors with popups begging for email addresses. Instead, make it easy for people to subscribe without trying to push it. This way, you'll be in a better position to earn valuable subscribers rather than those who aren't likely to become paying customers. In other words, you should use every opportunity to gather subscribers without disrupting people's experiences.

As we've already discussed, building a quality mailing list takes time, and it should be considered part of an ongoing marketing strategy. However, equally important as earning new subscribers is maintaining your existing list to keep it clean and, in the process, maximize deliverability. The first step towards maintaining a great mailing list is to remove or get back inactive subscribers, such as by asking them if they still want to receive your newsletters or offering them an exclusive 'we miss you' offer.


If you don't receive any response from your re-engagement campaign, you should remove subscribers who remain inactive. Although it's a legal requirement in the US and many other jurisdictions, providing an unsubscribe link is rarely particularly effective, since many people don't bother using it. Nonetheless, there are many reasons for subscribers to become inactive, such as they've moved away and your products or services are no longer relevant to them. Remember that, above all, your mailing list is not about the quantity of subscribers - it's all about the quality. 


Getting Your Timing Right


Sometimes, even the most engaging emails sent to the ideal subscribers still don't make it to your target audience. That's why getting your timing right is also extremely important. Unfortunately, there really aren't any set rules, so finding the optimal timing for your business will require extensive A/B testing. Every audience, industry and business is different, but there are a few general guidelines that should help you get started on the right track:


•   If your company sells consumer goods, late evenings tend to see high response rates among customers seeking last-minute promotions. Similarly, mid to late afternoons, just before the end of the business day, is often popular for making last-minute orders to still qualify for next-day delivery.

•   For B2B companies, lunch breaks and late afternoons often see the highest response rates as executives and managers are more likely to be catching up with non-essential correspondence and industry news and offers.

•   Email newsletter open rates are often highest just before working hours and during typical lunch breaks. Although people aren't as likely to make purchases at these times of day, there's a reasonable chance that they'll still read your content and even refer to it later.

•   As job-related apathy sets in later during the week, particularly on Thursdays and Fridays, many consumers are more open to receiving promotional content. This is especially the case in the travel and hospitality industries or any other that might involve weekend activities.

•   Unsurprisingly, email newsletters sent during the night receive the lowest open rates, with 10 PM being about the cut-off time. You'll also want to keep this in mind if you have an international audience spread across different time zones, in which case you'll want to segment your subscribers accordingly.


Just as important as social timing is finding the optimal sending frequency. Again, this requires a degree of trial and error, since every business and industry is a bit different. Above all, you'll want to avoid sending promotional emails out too often, since that's a very common characteristic of blacklisted senders. At the same time, not emailing regularly enough can lead to an ineffectual campaign, since your audience will forget about you. As a general rule, start with fewer emails and work your way up to find the optimum. 




With the correct approach, email can be one of the most effective tools in your marketing arsenal. However, it requires a long-term strategy combined with extensive A/B testing, a straightforward opt-in signup process and regular maintenance of your mailing list. If you can meet those criteria, you'll already be well on your way to email marketing success.