Here’s a view of my spam folder in Gmail. 

Notice anything? Very legitimate emails from reputable senders and companies are in here. So why is Google marketing them as spam?

Average number of spam emails sent per day (Sept. 2018): 300 Billion
—Talos IP & Domain Reputation Center

Email deliverability is defined as the ability to send an email and successfully have it delivered to the recipients’ inbox. Managing deliverability is paramount to driving business through email. It requires time and attention, and ongoing management. Here are four things you need to keep deliverability high…

Get the technical stuff right. There are a few key things you’ll need to partner with your tech team and/or ESP on.

• SPF: RetutnPath has a great post on these technical concept. Think of SPF as a way to certify your email. It’s the protocol that companies can setup to identify which of their servers are allowed to send emails. Since messages originate from a domain that is tied to a server, this helps certify that the domain owner who owns a server is authorized to distribute email from that server.
• DKIM: Domain Keys Identified Mail (great acronym, right?). As it sounds, this one is real complex. It uses a cryptographic approach to validate the original sender’s authenticity. A key is encrypted and “signed” into the proper place on an email. That key is then decoded from a public key to verify the sender.
• IP/domain: You’ll want to make sure you have dedicated IPs and domains to send your emails. Over time, your domains and IPs develop a “reputation” based either bodes well (or not) for your company as a sender of emails. The more care you take, the better your reputation.  

Send to people who want your emails. Stop sending to people who don’t want them.

• Explicit opt out: Sooo, you’re legally obligated to stop emailing people who have opted out. This is really a no brainer to getting your emails delivered. The window of time you have to opt someone out varies by country. In the US, for example, you have 10 days to honor someone’s request, which is an eon in digital standards.
• Implicit opt out: Here’s where you can really improve deliverability: look for measurable signals that people have “opted” out of your emails. How do you know if people have “opted” out without “outing out” – use behaviors like opens and clicks.

It’s all about engagement. When your email recipients stop opening and clicking your emails, stop sending to them.

• The window of time you use to determine “inactive” users can very – I’ve used a 6 month window. What that effectively means is that if a recipient doesn’t open or click a single email for 6 consecutive months, we’d ask them to confirm their subscription (via email). If they don’t actively confirm by clicking on that confirmation, we stop sending to them.  
• If you send 2-3 emails per user per day, you may want to be more conservative and use a three month window. To put it into perspective, 2-3 emails per day would mean that over three months someone has received about 225 emails from your company. If they didn’t open or click a single one, then yes, it’s probably time to ask them if they really want emails from you.

Make unsubscribes really, really easy. Like stupid easy.

• CAN-SPAM, CASL, GDPR: Yes, as we’ve established you are legally obligated to do so from the various laws that exist across the globe around email.
• Header and Footer: Here’s the thing, people are going to take the past of least resistance. If you only put an opt out in your footer, that means your user has to scroll all the way to the bottom to opt out. People will take the path of least resistance, and guess what email providers like gmail put conveniently right at the top of the screen: their button to mark as spam. You’d much rather have someone opt out via your company’s unsubscribe mechanism vs. marking an email as spam, as the latter is much more damaging to reputation.

Putting an opt out link in the header of your message increases the likelihood that someone who does want to unsubscribe will do by through your company’s process, preserving your reputation at the same time – assuming you do stop sending to them.