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Email deliverability - Are your email marketing efforts working?

Email deliverability

Most people are familiar with email marketing; it's a tried and true method for transactional and promotional messaging. But are you confident that your emails are being received as intended? According to Return Path, one out of every five emails never makes it to the recipient's inbox. Considering that many organizations send hundreds, thousands or even millions of emails to their subscriber base each year, it's safe to assume the potential amount of email marketing efforts lost due to deliverability issues can really affect the bottom line of an overall marketing strategy. 

What is email deliverability, and why is it important?

While some critics may equate email as old news in terms of marketing techniques, the fact is that email provides one of the highest ROIs in the industry. According to Campaign Monitor, for every $1 spent, email marketing generates $38 in ROI. Couple this with the fact that there is a market population of nearly 4 billion email users as potential customers, and it becomes hard to pass up on the opportunities that email marketing presents. This fact highlights the issues deliverability can cause as any time an email is blocked from a recipient's inbox, the investment's return is practically null. 

The concept of email deliverability has two main parts. The first being, does the recipient even receive the message at all? Many emails get blocked by email service providers (ESPs) before they even have the chance to be opened. The second issue has to do with inbox placement. It's the fight to end up in the primary inbox rather than Gmail's "promotional" tab, Outlook's "other messages" tab or, ultimately, the dreaded spam folder. 

What factors into email deliverability? 

There is a whole matrix of factors that can determine if an email will be blocked and where and what its inbox placement will be. There are legal requirements, sender reputation scores, IP warming strategies, domain authentication needs, spam complaints and much more to weigh in on when planning an organization's approach to email strategy. Let's break down a few main aspects to start.

Legal requirements

Legal isn't always a coveted topic to discuss, but depending on your needs, it can be vital. There are various laws surrounding email marketing, especially if any email recipients reside outside of the United States. Notably, consumers in the European Union are covered by the General Data Protection Regulation, or GDPR. This regulation covers a lot, but a central tenant of the policy surrounds data consent collection and storage. You can learn more about the details of how GDPR affects email in Litmus's blog on the topic. Luckily, if your email recipients are local to the United States, you don't need to worry about this much more than having a general awareness.  

However, the United States does have applicable laws for email marketers, CAN-SPAM, or the Controlling of the Assault of Non-Solicited Pornography and Marketing Act, is intended to protect consumers from unsolicited "spam" but has provisions that must be followed by all commercial (any type of marketing message) emails. A complete guide to compliance can be found on the U.S. government's site, but below is a list of the law's main requirements. Keep them handy; not only can they affect overall deliverability, but not adhering to them can be a costly mistake. 

  1. Be honest with email headers. It is required to keep the "from" and "reply-to" addresses true to the sender's identity. 
  2. Subject lines must be honest. Like the requirement for headers, don't be deceitful or intentionally misleading with subject lines; they need to accurately represent the email. 
  3. Acknowledge that it's an ad. It's unnecessary to write the word advertisement in the email as there is room in the law to interpret how this is disclosed but make sure it is clear. 
  4. Show where you are located. It is required that organizations add a physical mailing address somewhere in the email. 
  5. Include an unsubscribe/opt-out option. Like a physical address, every email needs a clearly defined way to opt-out for all future commercial messages. 
  6. Honor opt-outs promptly. The law gives ten days maximum for processing opt-out requests. 
  7. Stay on top of the rules. Ultimately, responsibility for CAN-SPAM falls to the organization; third-party entities and/or contractors are not responsible. 

Sender reputation score

An organization's sender reputation is akin to a Yelp page for email marketing. This reputation is tied to the IP address used either by a local email client like Outlook, or a more complex automation system such as Adobe Marketo. It is the most vital piece when it comes to email deliverability. It is imperative to keep a high sender reputation score to keep ESPs from filtering your messages into spam folders or blocking messages from your IP overall. There are many tools out there for checking sender reputation. This one from Sender Score is a good start. 

What hurts a sender reputation score?

Some common factors that can diminish a sender reputation score are any type of indicator that an email is unwanted by the recipient. This can include things like low open rates, rising bounce rates and complaints by the recipient. When an ESP such as Outlook analyzes its data and finds an IP address that is sending emails with little to no opens, a fair amount of bounces, and then some of the few people who opened it have complained or marked it as spam, it is likely to automatically start filtering future emails from the IP address as spam. This has a domino effect as it will quickly become harder to reach your recipient, and open rates will continue to drop.

Along with indicators of being an unwanted message, another trigger is when email copy is deemed too "spammy." When emails use verbiage like free or buy now, ESPs can flag emails as not being legitimate, thus lowering a sender's reputation. It is essential to make sure your email copy is intentional and not misleading; don't sound like you're trying to trick somebody into an offer. 

All these indicators are routinely checked by ESPs to keep an eye out for spam and maintain a happy user base, but they can go a few steps further as well. Spam traps are email addresses that ESPs own and maintain to catch emails being sent without proper permissions. These fake email addresses are often harvested from purchased lists or set up through situations where organizations don't capture proper opt-in requirements before sending an email to the contact. If caught sending to the contact that an ESP has set up as a spam trap, that IP address will most likely be auto-tagged as spam or even added to a blacklist that permanently blocks emails from your IP address to anyone with that email domain name. Remember, it is essential to get proper subscription permission before adding a contact to an email marketing list. Check out this resource by Hubspot to learn more about opt-in strategies. 

What helps a sender reputation score?

Two ways to start off right and increase sender reputations are IP warming and authentication. These techniques require a bit of planning and technical knowledge but are essential for large scale email marketing efforts. 

IP warming is simply adding a strategy to gradually increase the frequency of email sends from a new IP address. This strategy works to establish an identity with ESPs and a solid sender reputation score from the start. The process of IP warming can be complicated and take time. A detailed breakdown by Validity provides further information, but the idea is to start sending emails with a relatively small yet highly engaged portion of your subscriber list. Then double the number of emails sent every three to five days. The concept can be as simple as this or highly complicated due to the needs of a particular organization email sends. 

Authentication is a technical component that essentially is a proof of identification for different ESPs to check that a message is legitimately coming from the email sender. Two types of authentication are Sender Policy Framework (SPF) and DomainKeys Identified Mail (DKIM), and they work in combination to help ESPs fight domain spoofing and phishing scams.  

An SPF record is essentially a tool that authorizes an IP address to send email from the specified domain. This SPF record is stored with the DNS settings of an organization's domain. DKIM is a tool that works in both the DNS settings of a domain along with an encrypted signature in the header of an email. This server-level communication retrieves the encryption key from the DNS record of a domain and uses it against the DKIM signature in the email to authenticate that it is a legitimate message. On top of both of these authentication tools is a policy called DMARC that uses both tools in conjunction to authenticate emails. It is easy to sink deep into the technicalities of these authentication techniques, and learning more about DMARC is a great place to start. 

Finally, a great way to increase sender reputation and keep any negative indicators off of your IP address is to maintain content relevancy. The same general principle that applies to search engine optimization applies here as well. Content that is relevant, clear, concise and to the point will be rewarded with engagement. This relevancy includes keeping send frequency to a consistent schedule and only messaging subscribers when there is a beneficial offering for both the organization and the consumer. 

Three first steps to take

There is a lot to dive into when it comes to email deliverability. The larger the scale of email marketing efforts that are planned, the more needs arise to follow strict deliverability guidelines. This process can often take time and expertise, so let's review three first steps to start the discussion around email deliverability. 

  1. Follow CAN-SPAM and applicable commercial email laws.
  2. Start off on the right foot, follow IP warming best practices and authenticate properly. 
  3. Keep your content relevant to the subscriber, honest and on-brand. 

Keeping these three steps at the forefront of an email marketing strategy will ensure you start off in the right direction for ensuring your emails are delivered, which we know to be one of the most effective tools in a marketer's kit in terms of ROI and brand perception. At ddm, we have a team of professionals dedicated to email marketing and automation efforts that have experience starting from scratch to build strategy and execute campaign tactics for all types of organizations.

If you're interested in learning more about how your organization can improve its email deliverability standards or automate any portion of its email marketing efforts, please reach out at .