Email Deliverability: Strategies and Best Practices 2023

The Warmup Inbox Team
The Warmup Inbox Team

Email marketing campaigns can have a fantastic ROI, but they can only work if your messages make it to your recipients’ inbox. Email deliverability measures the ratio of total emails sent to the number of emails that are delivered. Improving your deliverability rate directly enhances the success rate of your email marketing efforts because more people are able to engage with your content.

Warm Up Your Email to Improve Email Deliverability

Instead of getting a new IP and immediately sending emails out to your entire subscriber list, warm up your inbox by steadily sending out more and more emails until you reach the number of emails you want to send in a day. This gives ISPs a chance to recognize your IP address and associate you with positive content.

Warming your IP works explicitly to build your reputation with ISPs, so you improve the health of your domain and email addresses. Slowly ramping up the number of emails you send demonstrates that your domain is trustworthy and does not send out spam mail.

Set Up SPF, DKIM, and DMARC Records

Authenticating your email address through the Sender Policy Framework (SPF), Domain Keys Identified Mail (DKIM), and Domain-based Message Authentication, Reporting, & Conformance (DMARC) verifies to ISPs that you’re a verified sender. These protocols are in place to help ISPs identify spam, spoofed emails, and fake emails before they make it into inboxes.

SPF is a DNS record that you add to your domain where you can specify the IP addresses and email servers that are authorized to send mail under the specific domains. DKIM uses encrypted signatures to verify that the content of the message hasn’t been tampered with and that the message is coming from the domain associated with the address. DMARC works as an extension of SPF and DKIM to allow you (as the administrator of your domain) to publish a public policy in your DNS records to specify which protocols are implemented and used when an outside email server receives outgoing mail.

Check Your Sender Reputation & Spam Score to Improve Email Deliverability

The number one reason that your emails aren’t making their way into your recipients’ inboxes is that your sender score is too low. ISPs will automatically reject emails from senders that fall below a specific score. Return Path offers standardized sender scores that assign senders a number between 0-100, and the closer you are to 100, the better. The score is determined through multiple factors, including traditional email metrics like unsubscribes and spam reports.

Ideally, you want your sender score to land above 80. Scores between 70 and 80 indicate that you need to make a few fixes, and anything below 70 means that something is really wrong, and you’ll need to make significant adjustments to get your score back up. If your sender score drops really low suddenly, check to see if you’re listed on any blocklists. If you are on a blocklist, you can remedy your sender score by warming up your IP address after you request to be removed from the blocklist.

Use a Recognizable Sender Name to Improve Email Deliverability

People get multiple emails from addresses like and, and it’s easy to cast aside emails that fade into the sea of other emails. However, if people see a name they recognize, they’re more likely to open the message. At the same time, messages that have a person’s name listed as the sender tend to perform better than team names because it feels more personal.

A fantastic way to increase personalization and recognition at the same time is to use your name and add “from [Business Name].” For example, if we were to send you an email, the sender name might pop up as “Alex from Warmup Inbox,” so you know that there’s a person on the other side of the email and that the message is coming from us.

In the US, it’s vital to stay CAN-SPAM Act compliant, or else you’ll face severe fines for every email you send that isn’t compliant. The easiest way to be CAN-SPAM compliant is to include an unsubscribe link in every email you send to your mailing list. Not only does this save you from paying fines, but it also gives your recipients the opportunity to ask you to remove them from your mailing list.

While that may sound like a negative, giving them a way to stop getting emails from you saves you from impacting your sender reputation through negative spam complaints. Without an unsubscribe link, consumers may simply flag you as spam, and every email you send to them going forward will be tossed into the junk folder.

Setup Authentication to Improve Email Deliverability

In the same vein as providing an unsubscribe link, having customers double opt-in when they sign up for your mailing list allows them to verify that they want to receive messages from you and that their email address is correct. This benefits you twofold because you are able to show ISPs that the recipient requested mail from you, and you won’t be sending emails to a bad address that will damage your deliverability rate.

The more popular form of opt-in is the single opt-in, which generally just requires that recipients check a box (or don’t uncheck one) to agree to receive emails from a company. The issue with single opt-in is that it frequently leads to spam complaints from customers who didn’t take the time to read the fine print and realize they were signing up for email blasts.

Many companies incentivize signing up for the mailing list by offering a promotional coupon or exclusive access to industry insights. This encourages users to authenticate their email addresses and engage with your content right off the bat. However, if you choose to run a contest as a way to gather email addresses for your mailing list, it’s especially important to have double opt-in measures in place just in case people give you fake email addresses just to enter the contest.

Avoid “Spammy” Words to Improve Email Deliverability

The easiest way to avoid the spam filter is to write like a human. While this may seem obvious, it can be easy to use marketing language in your emails that sounds a lot like spam emails. Hubspot offers a comprehensive list of words to avoid when putting together a marketing email. Some of the terms to avoid include:

  • Free
  • Chance
  • Here
  • Leave
  • Remove
  • Passwords
  • Hidden
  • Dormant
  • Miracle
  • Lose
  • Problem
  • Sample
  • Stop
  • Freedom
  • Reverses
  • Notspam
  • Search engines
  • Increase your sales
  • The following form
  • Will not believe your eyes

These words can trigger spam filters, but don’t use a thesaurus to blindly replace them (because, again, you want to sound like a human because you are a human). The content of your message should flow naturally, as if you’re talking to a friend rather than trying to sell something. If your text reads like a personal message and uses clear language, there’s less of a chance that a spam filter will flag it.