What is email deliverability?

Email deliverability refers to the percentage of emails that are delivered to a recipient’s inbox, as opposed to being blocked or sent to spam.

Strong email deliverability relies on keeping a clean and permission-based list, inbox monitoring, and overall sender reputation.

How to keep your email deliverability high

Before you start sending emails, it’s important to establish a sender reputation for your brand by warming your branded sending domain and dedicated IPs.

1. Warm and ramp your new branded sending domain

When using a new domain, build your sender reputation by:

Warming: Email warming is the process of gradually increasing your email account’s volume. You’ll need to warm if there’s any major change in your sending infrastructure—such as if you’re using the same domain but with a new platform, your domain is newly registered in the last 30 days, or your domain was never used to send email.
Ramping: Email ramping is the process of sending fewer emails at first and gradually increasing your volume over time. Remember, you’re introducing yourself to inbox providers, so make a good first impression by sending to highly engaged subscribers at first, then adding everyone else over time.

2. Warm and ramp your new dedicated IPs

If you have a dedicated IP, it also doesn’t yet have a sender reputation. Build your sender reputation by:

Warming: If you’re sending from a new dedicated IP, your messages are viewed with suspicion at first. As you establish your reputation, inbox providers will gradually begin to trust you. Start by sending to your highly engaged subscribers (30-day subscribers) and ramp volume from there.
Ramping: Start with smaller volumes of your highest engaged subscribers and ramp from there.

3. Get express consent to send email

Express consent means getting explicit permission from someone to send them marketing emails. The best way to get express consent is through website sign-up forms that set clear expectations from the start.

You should also consider using double opt-in for your sign-up forms, which is when you send a confirmation email asking all new subscribers to confirm their interest in receiving your emails.

4. Clean your list regularly

Run a list hygiene program that:

Suppresses invalid and outdated email addresses: Remove hard bounces automatically and develop a protocol for removing soft bounces.
Identifies unengaged subscribers: Every brand will set different criteria for what is considered an “unengaged subscriber.” For example, daily senders should only send to subscribers who have engaged within 30 days, weekly senders should send only to 90-day engaged subscribers, and so on. As an industry best practice, sending to people who haven’t engaged in more than 180 days should be limited to infrequent promotions or re-engagement campaigns.
Implements a sunset flow: Sunset flows are designed to phase out subscribers who are no longer engaging with your brand. You can use this flow as a last-ditch effort to win back their business, then delete or suppress anyone who is not responsive. They’re an excellent way to make sure you’re sending only to people who want to keep receiving your emails.

5. Offer an easy way to unsubscribe

Unsubscribe links in your email footer are required to remain compliant with regulations in most countries. One-click unsubscribes are also now required as part of 2024 Google and Yahoo sender guidelines.

The consequence of omitting one-click unsubscribes from your emails could be that they’re filtered as spam or bounced as blocked.

You may also want to provide people with a separate link to manage their email preferences, in case they only want to hear from you about specific things or less frequently. This is a great way to give people control over their inboxes, so they’re not flagging your emails as spam.

6. Optimize your email content for personal relevance

People are less likely to flag emails they feel are relevant to them. Here’s how you can start to optimize for relevance:

Segment your email list by website behavior, demographics, and lifestyle preferences. Avoid blasting your entire list with the same messages.
Personalize your messages with a recipient’s name and product recommendations tailored to their browsing habits.
Use concise language, provide valuable information, and create a powerful call to action (CTA) that rewards people for opening your email.

7. Monitor your email deliverability metrics

“Email deliverability” may be scored based on the following metrics:

Open rate
Click rate
Bounce rate
Unsubscribe rate
Spam complaint rate

Some marketing automation platforms analyze these metrics within a certain period to generate a score that can act as a proxy for sender reputation. For example, Klaviyo’s deliverability hub provides both an overall deliverability score and campaign-specific performance.