A high email deliverability rate is vital for email users, but it can be difficult to cling onto—especially as mailbox providers increasingly clamp down on spam. If you haven’t yet, go and check our email deliverability guide. Then come back and make sure you have cared about these 3 technical concepts.
Internet Service Providers are—understandably—concerned with making sure that users only receive relevant emails. As a result, somewhere between 45% and 73% of all sent emails are flagged as spam.
For email users, this is a largely positive move, but it can have a serious impact on the efficacy of email as a sales and marketing tactic. In a best-case scenario, a drop in deliverability leads to a ton of wasted time as you try to fix the situation, whether by improving your account’s deliverability or bailing on that account and starting a new one.
But improving deliverability and warming up new email accounts takes time—we’re talking weeks to months. It’s hard to forget about the number of emails you’re unable to send while you’re taking action to recoup your deliverability.
Maintaining good deliverability doesn’t have to be complex, but there are a number of technical elements involved in ensuring that your emails continue to land in the inboxes you want and need them to.
Here’s what you need to know:
Sender Policy Framework (SPF)
The Sender Policy Framework (SPF) is designed to confirm that you are who you’re claiming to be. It is indicated on the “From:” line in an email. This must match for corporate servers.
The SPF is very important to ESPs and filters. It’s designed to protect against spammers who are pretending to send from domains they’re not a part of. An SPF record is a type of DNS record that allows you to specify which IP addresses and hostnames are authorized to send email from your domain.
The email receiver will use the “envelope from” address of the email in order to confirm that the sending IP address was permitted to do so. This action happens ahead of the receipt of the body of the message. When the sending email server is not included in the SPF record from a specific domain, it will be flagged as suspicious and most likely rejected by the email receiver.
So what can you do to improve your SPF?
First of all, merge your SPFs from different servers into one “flattened” record. Some inbox providers also allow you to verify your SPF record—Gmail users can do this via the G Suite Toolbox.
You can also manage your mechanisms and qualifiers and ensure you’re using SPF with DKIM and DMARC (as detailed below). Another key tactic is to check the number of lookups for your SPF—but keep in mind that accounts with over 10 lookups won’t pass SPF.
DomainKeys Identified Mail (DKIM)
DKIM is best described as the key to unlocking an email message. This email authentication method is designed to identify forged sender addresses in order to block phishing and spam.
Originally formed in 2004 by merging two existing specifications, Yahoo’s Domain Keys and Cisco’s Identified Internet Mail, DKIM was developed into a new widely adopted authentication technique. All leading ISPs check incoming mail for DKIM signatures, making them extremely important to overall deliverability.
The DKIM is your “signed by:” line, and it should reflect the “From:” domain. Using DKIM, receivers are able to check that an email claiming to have come from a certain domain was actually authorized by that domain’s owner.
To put it simply, DKIM adds an encrypted signature to all outgoing messages. Email servers then use DKIM to decrypt the signed message header and confirm that the message wasn’t modified after it was sent. This signature is generated by the Mail Transfer Agent (MTA) and creates a hash value, which is a unique string of alphanumeric characters sent with an email.
After receiving the email, the receiver is able to verify the DKIM signature using the public key registered in the DNS. This key is used to decrypt the hash value in the header and recalculate the hash value from the email. If those two DKIM signatures match, the MTA can be sure the email hasn’t been altered, confirming it was sent from the listed domain.
It’s important to set up DKIM for your domain in order to maximize deliverability, but if you don’t, Google will use its default DKIM domain key—as long as you’re using Gmail or Google Apps, of course.
Domain Message Authentication Reporting and Conformance (DMARC)
DMARC also helps email receivers verify incoming messages with the most sophisticated methods of all three.
In order to pass the DMARC test, messages must be authenticated by either SPF, DKIM, or both. In addition, the authenticated domain must match the domain in the message “From:” header address.
And what happens if your email doesn’t pass DMARC? DMARC will suggest to the incoming server one of three possible directions:
- Take no action on the message (treat it as though no check ever happened)
- Mark the message as spam and deliver the email to the recipient’s spam folder
- Reject the message
However, it’s important to remember that a DMARC policy is more of a request than an obligation. The DMARC policy instructs the receiving server to handle the emails according to the policy, but email receivers still have the ability to use a local policy and reject the DMARC request.
While DMARC is not currently required for deliverability across the board, it is becoming increasingly important for sending to large organizations, so it’s essential that email users are on top of it.
All this technical jargon can be confusing if you’re not familiar with it, but it’s important to understand what goes on behind your screen in order to maximize the deliverability – and therefore the effectiveness – of your emails. Mastering these three elements of email deliverability will go a long way in helping you ensure that your emails reach their intended destinations.
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Non-Technical Methods to Improve Deliverability
So, you’ve ensured that your sending infrastructure is as healthy as possible—so your deliverability is guaranteed to remain high, right?
Inbox providers can downgrade your deliverability for a multitude of sins, and not all of them are technical. But with a bit of research, a lot of the issues that will leave your emails floundering and unread in recipients’ mailboxes can be easily avoided.
Avoid Spammy Language and Content
Using spammy language is a surefire way to get your emails flagged as, well…spam.
For this reason, steer clear of terms like “100%”, “bargain”, “credit”, “discount”, and “for just $X”, as well as other words of that kind. In fact, it’s a good idea to avoid the dollar sign in general. Other tips include keeping the formatting simple—like not using too many words in bold or italics—and avoiding emojis.
This should go without saying, but you should also avoid profanities in emails—both for deliverability reasons, and to avoid deterring potential prospects.
Think about your text-to-image ratio, too. Using too many images or gifs could trigger a spam filter. If you must use images, the best approach is to include just one.
Links are another potential pitfall, as they’re seen as a sign of spammy emails. Try to limit the number of links in your emails, and avoid linking to sites with a poor reputation or to any links that redirect. Always check if a link works before including it in an email—it’s a simple action that could make all the difference.
If you’re warming up a new account, however, it’s best to avoid links and images entirely until you’ve gotten your deliverability at the level you need it to be. And even then, keep them to a minimum.
Don’t Send Unwanted Emails
While it’s relatively simple to avoid language that signifies spam, it’s also important to refrain from “spamming” people who didn’t sign up to your email list. Sending unsolicited emails is unlikely to help you hit your goals, but it could harm deliverability if recipients flag your message as spam.
Whenever you send promotional emails, make sure you include an easy and obvious opt-out option for people to unsubscribe from your list if they don’t remember signing up or don’t wish to receive emails anymore.
Only Send Relevant, Personalized Emails
Being caught in an automated spam filter isn’t the only way to reduce deliverability: remember, humans can mark your emails as spam too.
When people mark an email as spam, it helps mailbox providers work out what is and isn’t spam. If your emails consistently get flagged as spam by recipients, you can wave goodbye to your high deliverability.
Finally, don’t forget the golden rule. When sending emails, the best way to avoid being flagged as spam is to ensure that every single email that goes out is both relevant and personalized to the recipient. Don’t be afraid to seek help from other professionals, such as an English tutor. This will help you write a well-written letter.