Email & SMS

Email Deliverability: 12 Best Practices for Marketers [2023]

By Tinuiti Team

We all know the level of effort that goes into getting an email campaign out the door—concepting, promo planning, writing, designing, coding—but once you hit the send button, where is your email going? Is it landing in your subscriber’s inbox in all of its glory? Or is it disappearing, hidden in their spam folder never to be seen? Seeing an otherwise flawlessly executed campaign land in the spam folder is a lifecycle marketer’s worst nightmare. 

Here’s why deliverability should be top of mind at all times.


What Is Email Deliverability?


Email deliverability refers to whether or not your emails make it into subscriber inboxes. It’s the first step in a successful email campaign. If your emails aren’t reaching subscriber inboxes in large percentages, it decreases your chances of meeting other email metrics.

Other numbers you might be concerned with when it comes to email campaigns include:

1. Open rates – This is the percentage of people who actually open the email. If you send 100 people an email and 20 people open the message from their inbox, your open rate is 20%. After the iOS 15 update in September 2021, this KPI is inflated, but consistency in this KPI is key to monitoring deliverability.  

2. Click rate – This is the percentage of people who click on a link in your email. If you send 100 emails, 20 are opened, and 5 people click on a link to find out more, the click rate is 5%.

3. Bounce rate – Bounce rate refers to how many emails couldn’t be delivered, or “bounced.” This figure helps determine your delivery rate.

Email deliverability is impacted by a range of factors, including:



Sometimes it’s obvious why your deliverability has dipped – ESPs can provide some visibility here – but often, you need to use a tool to find some of the more niche or nuanced reasons.


Why Email Deliverability Matters


Obviously, the more emails that show up in the inboxes of your audience, the better your campaigns can perform. But there are other reasons this metric is so critical. 

Deliverability matters because you have important information to convey to your audience and customers. Imagine, for example, that one of your users needs to reset their password. The process usually involves email verification. If that person isn’t getting emails from you—or emails are falling into their spam folder—they may have a hard time resetting their password. The frustration of email deliverability issues could even cause you to lose customers.


What’s a Good Email Deliverability Rate?


This answer depends on your business and your industry. Ideally, you want your email deliverability rate to be between 90% and 100%, though 100% can be difficult to achieve. While a lot of things are in your control, you don’t have complete control after you hit send on an email or marketing blast. In general, it is recommended to keep spam complaint rates below 0.1% to maintain positive inboxing. To understand what a good email deliverability rate might be for your business, consider factors such as:



12 Best Practices to Improve Your Email Deliverability


Each email inbox provider, such as Gmail or Yahoo, uses its own algorithms to determine where your email goes once it’s handed off by your email service provider. Those algorithms can slot your emails into folders including spam, promotions or social. Additionally, email users might set up their own folders with automated sorting.

You want to increase the chance that your email shows up in prime inbox real estate—that’s the main inbox, where people are most likely to see and interact with your message. The best practices listed below help you achieve that goal.


1. Improve Your Reputation


How an ISP or email inbox provider treats the emails you send often depends on the reputation of the domain and IP address the emails come from. When an unknown domain suddenly sends out thousands of emails, it can look like spam. And if you’re sending a bunch of messages no one ever engages with or users are reporting as spam, that’s bad for your overall reputation.

ISPs may run checks on emails—including checking the reputation status of your domain—before they deliver them. Poor reputation equals poor email deliverability. 

Counteract this issue by working to build a good reputation from the very first email you send. 

If you’ve had less than stellar sending practices in the past, your domain will have a tarnished reputation. On a similar token, if you’ve recently updated your sending domain, you’ll need to build up a positive reputation from scratch. 

“To win favor from inbox providers in either scenario, run through a warming process—only mailing to highly engaged contacts until you see improvements—in order to build up credibility as a sender. At Tinuiti, we offer a proprietary warming process to improve sending reputation with all internet service providers, as it is not a one size fits all approach.” 

Bre Barkley, Strategist, Lifecycle Marketing at Tinuiti

Bre Barkley, Strategist, Lifecycle Marketing at Tinuiti

2. Create High-Quality Relevant Content


One of the best ways to create a good email marketing reputation is to consistently send the kind of content your audience wants to see. When you have high open and click rates, that signals to ISPs and email providers that you have a good reputation with your subscribers, which makes it more likely you’ll end up in the main inbox.

Plus, when people are used to receiving high-quality content from you, they’re happier to find your message in their inbox. They may open it sooner rather than waiting until later, ensuring the email doesn’t get buried and forgotten.

Additional tips include:



3. Practice Email List Hygiene


List hygiene involves validating your list before you send emails. For example, you should always ensure you’re not sending emails to people who have opted out of those types of communications. If subscribers or contacts haven’t engaged with you at all in 6 months or a year, you may want to remove them from your list as inactive. What is considered an “active” audience varies by brand and an audience analysis should be performed to determine what your typical engagement time frame is.  

It’s also a good idea to remove emails from your list if your messages are bouncing. That’s especially true if the domain name of the email is spelled wrong—yahooo or gmaiil, for example. These look like innocent typos, but if you keep sending emails to those addresses even though they constantly bounce, you might come across as a spambot.  Email service providers typically have a default limit of the number of bounces a subscriber can have before being removed from our list, so be sure to check this setting within your ESP.   

To prevent potential issues, it’s crucial to run re-engagement campaigns for unengaged contacts and regularly remove inactive or dead contacts from your list. This became even more important after the iOS15 update. Additionally, including click engagement data alongside open rates helps mitigate the inflation of machine opens.


4. Watch Your Bounce Rate


A message bounces when it can’t be delivered. High bounce rates can indicate technical issues with your list that you should look into. You typically receive automated responses with some indication of why a message bounced. 

While there are numerous reasons for bounces, they tend to fall into two main categories:

Soft bounces – These are related to temporary problems, such as email server issues. You can try again with these recipients in the future.

Hard bounces – These relate to errors that are permanent. In some cases, they may be related to strict filters. In either case, you usually want to remove these emails from your list.

Pro-tip: Hard bounces need to be removed from your mailing list immediately, which most email service providers do automatically.  Subscribers who soft bounce more than 3 to 4 times should also be removed from your mailing list, and most ESP’s have a limit for soft bounces as well before removing subscribers from your list.  


5. Don’t Buy Email Lists


You only want to send emails to people who have agreed to receive your messages and are interested in your brand, service or product. When you buy lists, you can end up with random recipients that don’t care about your messaging. They may report your email as spam or simply ignore it, neither of which is good for your reputation.

Email lists can contain inactive, inaccurate, irrelevant, or even honeypot addresses. Honeypots refer to fake email accounts created by certain ISPs and distributed in disreputable sources, often ending up on purchased email lists. If you send emails to these blacklisted addresses, your deliverability is likely to be severely impacted.


6. Make It Easy to Unsubscribe


It might sound counter-intuitive, but the easier it is to unsubscribe from your list, the better. People who don’t want to hear from you will leave anyway. And if you don’t provide a path for that exit, they may use spam reporting tools to get your emails out of their inbox in the future.

Getting reported as spam is worse for your reputation than an unsubscribe. It can mean that more of your messages to other email users end up in spam folders.

Pro-tip: On your unsubscribe page, give subscribers an option to control what kinds of emails they get or the frequency so you can retain them without harming deliverability. Be sure to comply with the subscriber’s preferences to avoid having them report as spam. 


7. Send a Consistent Volume of Emails


Following a consistent sending cadence with your emails creates a better trust relationship with your audience. For example, if subscribers expect to see your emails once a week but you ghost them for three months before showing up again, they may not trust you as much. They might also have forgotten all about you, which reduces open rates.  

At the same time, sending too many emails can annoy your audience, sparking more spam reports or unsubscribes. Find what works for your audience and stick to it.

Pro-tip: If you wish to adjust sending frequency to be higher or lower, ramp up or down slowly and monitor deliverability in the process. Be sure to keep in mind the volume of automated messages you have going out as well.


8. Segment Audiences


By segmenting your audiences, you can address the specific preferences and needs of each group of people. That helps increase open rates, engagement and click throughs—all of which increases email reputation. When you segment your audiences, you have the opportunity to create a more personalized and relevant experience. By sending highly targeted communications, you decrease the appearance of spam.

Here’s an example of how segmenting audiences can work in your favor: 

If you’re a high-frequency sender, and everyone on your list is being mailed every single campaign you send, you’re likely to see higher than normal spam complaint rates, which will similarly land you in the spam folder. Consider breaking your audience into frequency tracks based on engagement, mailing more frequently to those who open and click regularly, and pulling back the cadence for less engaged contacts.


9. Authenticate With DKIM, SPF and DMARC


Use authentication technologies that help identify you to email providers. Some options that work as a sort of digital signature, confirming your status as a valid sender, include:



10. Check Your Sender IP Address


Check the reputation of your sender IP address with tools such as Google Postmaster or Validity. If you have a poor sender IP reputation, as already covered, your email deliverability rate may suffer. Some actions you can take include:



Pro-tip: If you are on a dedicated IP address, your reputation is solely based on your sending, making it important to closely monitor your program and be more swift to make adjustments if your deliverability dips. 


11. Avoid Spammy Text


You may have noticed a trend in this guide: anything that can be interpreted by email technologies or users as spam is bad. That includes text in your email subject lines and content.

Keep up with spam trigger word trends. These are words that are commonly used by spammers and may be used to filter content out of inboxes.

 Some examples include:



12. Keep Your Content Simple


Keep emails to a few hundred words or a couple of paragraphs at most. Avoid embedding video or anything that requires Javascript or Flash, as these aren’t always supported. Instead, use images, animations, and links to get the click. 

Don’t include attachments in your marketing emails. People don’t trust them and may worry that you are sending them a virus. Instead, put the documents or downloads on your website and link to those pages.

Create HTML and plain text versions of your emails. Most ESPs already convert HTML into plain text through Multipurpose Internet Mail Extensions (MIME). This allows both a plain text and HTML version to be emailed at the same time, allowing the email client to choose what version to place in your readers’ inboxes based on their preferences.


Other Tips & Tricks to Improve Deliverability


Email marketing is a complex process, and there are many ways to improve deliverability and engagement. Here are a few more:



How to Test & Measure Your Email Deliverability

Many marketers believe their ESP can provide a reliable view of their email program’s deliverability; just look at how many emails were ‘delivered’, or the sender’s ‘delivery rating’ as an indicator of whether or not emails are landing in the inbox. Unfortunately those numbers aren’t going to give you the complete picture. Your ESP’s reporting can only tell you whether or not the message was successfully handed off to the ISP’s servers. It can’t tell where it’s going once it reaches the ISP. 

So it’s time to take matters into your own hands. There are two key areas to look in order to determine inbox placement:

1. Track Open Rates by Domain

A tanking open rate or small declines over time can indicate that you’ve got a deliverability problem on your hands. If your emails are landing in the spam folder, chances are they’re not getting opened. 

Some ESPs offer out-of-the-box reporting for engagement metrics by domain. If your ESP doesn’t have this reporting, take a few minutes to create segments for the top 5-10 domains in your audience. Utilize these segments for regular deployments in order to track open rates by domain. In general, Gmail, Verizon (AOL and Yahoo domains), Microsoft (Hotmail, Live, MSN, Passport, and Outlook), and Apple will be the big ones to watch, and smaller domains can be bucketed together. This segmentation strategy will help you identify exactly which domains are having issues, enabling you to chart a path forward to get back into the inbox. 

2. Utilize Inbox Tracking Tools

For more detailed data on your inbox placement, consider contracting with a deliverability monitoring service like Everest by Validity. Theis vendor utilizes seed lists (actual live email addresses) to determine exactly where your email is going, telling you not only if you landed in the inbox, but in the case of Gmail, helping identify if your messages are in the Primary or Promotions tab. While these helpful tools will allow you to catch wind of issues, they’re not always 100% accurate. Avoid unnecessary panic by monitoring open rates alongside for more realistic tracking. 

The sheer number of factors to consider when it comes to deliverability can be overwhelming. Take the first step toward long-term deliverability health by getting a clear view of current inboxing to help key into areas for improvement.


Final Takeaway


By upping the ante on email quality and paying attention to metrics and subscriber behavior, you can support email marketing campaigns that perform better. For help with this process, reach out to our Tinuiti Lifecycle Marketing experts.

Editor’s Note: This post was originally published in July 2019 by Kellie Collins and has been updated for freshness, accuracy, and comprehensiveness.


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