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Learning to improve Gmail deliverability

The inbox is a crowded arena, but you can’t compete if you don’t even make the cut. In this article, we’ll look at how you can improve your email deliverability with Gmail and overall deliverability.



The inbox is a crowded arena, but you can’t compete if you don’t even make the cut.

Any email sender will tell you email deliverability is a key success indicator and a surefire way to increase their return on investment (ROI). After all, getting your email to land in your subscriber’s inbox is the first step to improving brand awareness, customer engagement, and subsequent conversions.

In this article, we’ll look at how you can improve your email deliverability. Then, we’ll shift our focus to Gmail, one of the largest Email Service Providers (ESPs) that most likely makes up the lion’s share of your subscribers’ inboxes. We’ll look at some factors which impact your Gmail deliverability and best practices to increase your overall deliverability.

How do you improve your email deliverability?

We find that email deliverability is half science and half art, by which we mean that some factors affecting deliverability are more quantifiable than others.

For instance, here are some elements on the “science” side of deliverability:

  • Domain alignment

  • Email authentication protocols (including SPF, DKIM, and DMARC)

The “art” side of deliverability consists of the following:

  • Permissions

  • Frequency

  • Segmentation

What does this all mean? We’ll dig into each of these elements of email deliverability below.

What’s the science of email deliverability?

Let’s start with the “science” side of things. These are elements we can make specific recommendations about to help you avoid email deliverability issues. Below, we’ll look at how you can implement domain alignment and set up email authentication protocols.

How do I implement domain alignment?

Domain alignment ensures that your authenticated email domain aligns with the domain in the “From” header. The header is where you include the recipient, sender, and subject line. In other words, domain alignment means that the email address your email campaign sends from is the same as your authenticated email domain instead of from, for instance. Below, we’ll go over how to set up email authentication protocols, but first, let’s look at the benefits of aligning your domain.

The benefits of aligning your domains include:

  • Your sending domain appears more trustworthy to ESPs, which can be the difference between landing in the inbox or hitting the spam filter.

  • All your hyperlinks and tracking links will redirect using your own domain instead of another domain, like

  • Your “From” address will display as your own domain and not as “Sent via Mailgun.”

  • You’ll be able to take control of your sender reputation via your sending domain and links inside the emails.

How do I set up email authentication protocols to improve deliverability?

Before aligning your domain, you need to set up email authentication protocols that help build legitimacy in your headers. We’ll briefly discuss what this means, but you can check out our email authentication tutorial for a complete walk-through.

Enabling your email authentication protocols requires setting up the following:

These records tell Internet Service Providers (ISPs) that you’re who you claim to be, rather than someone who could be spoofing a legitimate business. There isn’t a lot of wiggle room for these deliverability factors, so they must be set up correctly.

What’s the art of email deliverability?

Now let’s move on to the “art” side of email deliverability, which is infinitely more flexible and challenging. Back in the day, you used to be able to send out an email blast and reach everyone on your email list. But email blasts don’t work anymore – they lack that personal touch. Any email marketing specialist will tell you that personalizing your emails is crucial to reaching your target audience.

In the context of deliverability, personalization goes deeper than content and email design. You’ll also need to consider permission, frequency, and segmentation. We’ll look at each of these below.

What permissions do I need to improve deliverability?

Make sure that you’re only sending emails to people who have opted-in to receive them, or have permission to send to in the first place. If you’re sending email messages to people who haven’t allowed you to contact them, you’re sending spam. The definition of spam might change over time, but the core values of permission and consent remain firm. 

How often should I send emails?

Sending your messages at the right time is critical to your deliverability, and no two senders will have the same sending frequency. For example, a recruiting agency and a party supplier shouldn’t have the same email cadence. The recruiting agency might send an email as frequently as once a day, whereas the party supply company will only send seasonal messages. 

Your sending frequency will largely depend on your industry and user preference. To better your deliverability, give the power of sending frequency over to your audience, and ask them how often they would like to receive your messages. 

How can I employ segmentation in my email practices?

Segmentation plays one of the largest roles in determining your email’s deliverability. When we think about building out segments for better deliverability, there are two approaches we must consider:

  • Mailing list segmentation: Breaking down a large email list into actionable segments. You might separate users into three categories: active, semi-active, and inactive. The active list includes users who have engaged with your messages in the last 90 days, semi-active users who last interacted between 90-120 days ago, and inactive users who haven’t responded to your email messaging for over 180+ days. Once you break down your list into these segments, we highly recommend removing your inactive portion, since some of those addresses could now be spam traps. Before you do that, though, send them a reactivation email asking them if they still want to hear from you – you might still be able to re-engage some of those recipients.

  • Infrastructure segmentation: Segmenting your sending IPs, domains, and subdomains. For larger senders, split your sending across several dedicated IPs that separate your transactional emails from your marketing emails to preserve your IP reputation. Use a similar breakdown for your subdomains as well. Your marketing messages shouldn’t interfere with your transactional messages – you can break these down with subdomains to keep your domain reputation as pristine as possible. 

How does this all relate to Gmail deliverability?

Gmail inboxes generally make up over 50% of a sender’s email list, so it makes sense to set up your current sending infrastructure and strategy to maximize your deliverability with Gmail. Even though Google has a highly sophisticated email system, we have a good idea of what works.

We know that Gmail relies heavily on domain reputation based on Google Postmaster Tools. This is mainly because most smaller senders opt for shared IPs. While IP reputation is still important, a shared IP’s reputation reflects the sending habits of multiple senders, so the reputation isn’t accurate for each sender. Domains, however, are tied to one sole sender and speak to your individual sending practices and reputation. That’s why it’s so important to break down your sending into different subdomains so your conflicting reputations won’t impact one another.

Domain segmentation also allows Gmail to better categorize your emails into their different inbox tabs (Primary, Social, Updates, Forums, and Promotions) If you have a subdomain dedicated to shipping notifications, those emails will show up under the Updates tab. Regardless of which tab your email lands in, your email is still landing in the inbox, not the spam folder.

There’s a misconception about the Primary tab only being the inbox, and there’s no golden rule for landing in the Primary tab. Attempting to land in the Primary tab can do more harm than good, because users likely don’t want promotions in that tab and are more likely to mark those messages as spam. Gmail tabs were introduced to organize the high volume of messages coming into inboxes, so allowing them to work in your favor helps your chances of engagement.

What are some factors which impact your Gmail deliverability?

With Gmail making up the lion’s share of your subscribers’ inboxes, let’s look at some factors which will impact your Gmail deliverability:

  • Abuse complaints: Avoid these at all costs! Abuse complaints occur when your recipients mark your email messages as spam. This usually occurs for one of two reasons: your recipients didn’t sign up to receive your emails, or they can’t find the unsubscribe button. You can troubleshoot this with better HTML email design and ensure that you have a clearly visible unsubscribe option.

  • Engagement: Gmail examines the extent to which each subscriber engages with your domain in comparison with other domains. This type of relative engagement may be adjusted based on your sending reputation. To maintain good engagement with your subscribers, you can send relevant emails with relative frequency. However, as we mentioned above, don’t send emails too frequently, because they might misconstrue your enthusiastic messaging for spam.

  • Authentication: Are you who you say you are? If you are, you have nothing to worry about. Jokes aside, as we mentioned above, be sure to set up email authentication protocols so Gmail can easily verify your email’s authenticity and legitimacy.

What are some best practices to improve email deliverability for Gmail?

Let’s look at some best practices to improve your Gmail deliverability. Some of these methods are Gmail-specific, but most are also applicable to other email clients your subscribers may use. Let’s dive in!

If you want to improve your Gmail deliverability:

  • Validate email addresses: Keep your email list updated and verify email addresses to prune out invalid users. This minimizes the number of emails that bounce when you send out your email campaigns. It’s a bit Farmville-like, but having a better delivery rate improves your Gmail deliverability.

  • Add an unsubscribe option: Some subscribers mark emails as spam because they can’t find the unsubscribe option. While subscribers won’t necessarily see the difference, marking your email as spam registers an abuse complaint against your email marketing efforts and negatively impacts your sender reputation.

  • Authenticate your messages: As we mentioned above, it’s important to set up your email authentication protocols. When a mail server receives your email message, it tries to authenticate the legitimacy of your email. In other words, it checks if you (the sender) are who you say you are by consulting your SPF and DKIM records.

  • Test your emails: Use seed testing like our Inbox Placement tool to see how you perform. And finally, send test emails to yourself or use pre-deployment software to see how your email will render on various email clients.

Use a dedicated IP: We go over dedicated versus shared IPs in more detail elsewhere, but opt for a dedicated IP if you want to have sole and complete responsibility over your sender reputation.

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Wrapping up

And that’s Gmail deliverability in a nutshell! Ready to knock on Gmail’s door and deliver your messages? Take a look through these email deliverability best practices to keep your emails away from the spam folder, and join our newsletter to get these tips in your inbox every week!

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