Deliverability Dos and Don'ts
Taking steps to make sure your emails actually reach your customer’s inbox is essential to getting your messages opened and read. Email deliverability hinges on sender authentication and reputation.
This primer covers some basic steps to ensure healthy deliverability. We’ll talk about setting up email authentication, best practices for email content, tips for testing, and some things to watch out for.
Set up email authentication
If there’s one takeaway or to-do to glean from this primer, it’s to set up your email authentication already!
The deliverability experts at ReturnPath write in their excellent guide to email deliverability: >As a legitimate business, authentication is not optional; it is essential to securing your brand and online reputation.
Without authentication, you directly lower your chances of emails making it into the inbox. The first thing we check when troubleshooting deliverability problems for our customers is whether you've set up your authentication. Seriously, set up your email authentication.
To do this, you’ll have to configure a few DNS (Domain Name Service) records, which are like a digital signature that confirms your identity to mailbox providers. You'll add SPF and DKIM records to signal: “Yes, I own this domain and I allow Customer.io to send emails in my name. When you, mailbox provider (gmail/hotmail/yahoo), see this signature in emails I send, it’s fine… I allowed them to send. These aren’t phishing emails.”
Your sending authentication settings in Customer.io are here, where you can configure DNS records for each domain you'd like to sign.
Best practices for deliverability health
There are many additional aspects that go into deliverability. Like other types of wellness goals in your life, approach deliverability like maintaining your health—an ongoing project.
While mailbox providers have varying rules to determine inbox placement, they all look at quality of engagement. Make sure to keep in touch with permission, relevant content, while testing for any issues.
Have a sensible frequency of emails instead of defaulting to an intermittent, one-off communication strategy. You know how it’s easy to forget someone’s name if you met them awhile back but haven’t seen them since? Good relationships grow from repeated positive interactions, not just one exchange.
Some people make the mistake of staying too quiet, thinking that the less you reach out, the better your deliverability is. But that creates the problem of losing familiarity and momentum: every time you do decide to reach out then, your reader might have forgotten who you are and mark your message as spam. Plus, when there are long gaps until the next communication, you might lose the attention of anyone whose email address has changed.
Send only to people who have opted in to receive communication from you. (As a policy, Customer.io sends only permission-based email.) Provide clear and easy options for people to unsubscribe or update their contact information.
Check the health of your subscribers regularly. Pay attention to your campaign metrics, and test how best to prune people who haven’t opened in a very long time. Just because people opted in once doesn't mean you have continuing permission forever. Lack of engagement is a good warning sign.
Create quality content for your audience and send information relevant to their interests. That means using segmentation to tailor your recipients and knowing your audience to understand what they find most interesting and relevant.
Test your email content
Keep an eye out for drops in open rates, having emails landing in spam folders, or a spam rate higher than an average .02%. These are signs to check for spam filtering issues and run some tests in tools like Litmus or Email on Acid to diagnose issues. Head here for an overview of how to test your emails for spam issues.
Don’t forget to add your DNS records.
Don’t just do blanket email blasts. (Make emails, not war!)
Don’t buy lists. Remember that whole building relationships thing? Adding people without explicit opt-ins means you never got permission to email them.
Don’t send on behalf of users with their email address when sending messages like invite emails. This often causes deliverability problems. Instead, send these messages out from your domain email address.