Education
Email Deliverability: The Complete Guide to Maximize Growth
Hannah Permell
Learn why email deliverability is the most important part of email marketing, how to get into your customer’s inbox, how to monitor your sender score, and what you can do if you have a bad sender reputation.

What’s the most important part of email marketing?

You might think it's your subject lines, calls to action, or click through rates.

While these are all important elements of email marketing, they’re also all wrong answers to that question.

The correct answer is email deliverability. 

Your customers can’t read your subject line, act on your CTA, or click any of your content if your email never made it into their inbox in the first place.

Without deliverability, nothing else matters.

As a growth marketer you want to make sure you are practicing consent based email so that you can get into your customers’ inboxes consistently to communicate with them.

Email Deliverability 101: The Factors That Matter 

Your sender score, also referred to as sender reputation, is what determines whether your email lands in your customer’s inbox or ends up in the spam or promotions folder. 

A sender score is a number between 0-100 that is assigned to every email sender to measure the health of your email strategy and reputation. 

There are two parts to a sender score: your positive signal and your negative signal. 

Just as their names suggest, positive signals improve your sender score and negative signals degrade your sender score. 

Sender Score Positive Signals 

There are four positive signals that contribute to the improvement of your sender reputation.

  1. Email Opens - are recipients actually opening your emails, or trashing them before reading them?
  2. Click Throughs - do people click on your call to actions or ignoring the links you place in the email?
  3. Responses - have you been getting replies from recipients or are your emails going unanswered?
  4. History as a sender - have you been consistently sending emails that get opened, clicked, and responded to by recipients?

Sender Score Negative Signals

There are also four negative signals that can contribute to a decrease in your sender score.

  1. Hard Bounces - the email failed to deliver for permanent reasons such as an invalid email address.
  2. Complaints - are your emails being marked as spam by recipients?
  3. Deletes without opening - do recipients send your emails straight to the trash?
  4. Buying email lists - did you purchase your email list from another vendor?

A big red flag for your negative signal is buying or scraping email lists. If you do this, you’re much more likely to have your emails marked as spam, deleted without being opened, and poor open and click through rates. 

The spam folder is where good emails go to die. You want your emails to stay out of that folder. 

How to Avoid the Dreaded Spam Folder

Staying out of the spam folder is obviously best practice. But it’s not just good for your sender score to land and stay in your subscribers’ inbox -- it’s also good for your relationship with your customers. 

If you built your email list authentically and honestly, being marked as and sent to spam is a good indication that you need to work on customer relationship management. 

Just because your subscribers opted in doesn’t mean they won’t send your emails to the junk folder if they feel you’re spamming them. 

Here are a few things you can do to ensure you’re sticking to the inbox:

#1. Keep Your List is Warm 

Communicate with subscribers on a regular basis. 

Regular communication helps to ensure that subscribers won’t forget that they signed up for your list and mark you as spam. 

Be sure to send a double opt-in and a welcome email to your new subscribers, so that they can confirm that they want to be on your email list. 

#2. Don’t Spam Your Email Subscribers

Sending too much email can also create some problems. Your subscribers don’t want to be spammed with 2-3 emails a day from you. Inboxes can get super crowded. Be sure to space out your email communications and cross check your email drips with your campaigns to ensure that you’re not over communicating with your subscribers. 

#3. Make Sure Email Addresses are Up to Date. 

It’s not uncommon for people to change their email addresses over time, especially when they start a new job. If you’re sending emails to addresses that are 18 months or older, they are likely to end up in spam. 

#4. Don’t Use Spam Trigger Words in your Subject Line. 

Spam trigger words are keywords or phrases that email providers have noticed are commonly associated with scams. The use of these keywords and phrases trigger spam filters to send these emails to the spam folder.

It is best to avoid trigger words such as: 

  • Offer
  • Increase Sales
  • Winner
  • Order Now
  • Promotion

These words have a bad reputation and will likely land your emails in the spam folder. 

Now that you know how positive and negative signals affect your sender reputation. It’s time for you to find out what your sender score actually is.

How to Monitor Your Email Sender Score

Your email sender score is a number between 0 and 100 that is used to determine the quality of your email sender reputation. 

If you have a sender score between 0-70, this is a major red flag. You have some serious work to do to repair your reputation (keep reading to find out how you can do this). 

A sender score between 70-80 is not too bad but needs some work. Optimize for best email practices to improve your score. 

A score between 80-100 is fantastic. Keep up the great work.

Unsure what your sender score is? You can use this tools to find out:

  1. Google PostMaster. Google has a free tool that will tell you what Google thinks about your sender reputation. You can use it to monitor your deliverability health and resolve problems as they are flagged. 
  2. Check your Internal ESP (Email Service Provider) Metrics. This is the platform you use to send your email such as GetResponse, Drip, MailChimp etc. If your email engagement rate is dropping or your unsubscribe rates are climbing, this is a red flag that you are getting a bad sender reputation and your deliverability is at risk. Keep an eye on these metrics. 
  3. MXToolBox. This is a free tool that will give you a health score, and feedback on what needs to be fixed for you as a sender, to keep your deliverability health in check. It will also let you know if you’ve been blacklisted.



Oh no! You’ve checked your sender score and found out that you have a bad sender reputation. What do you do now?

How to Fix a Poor Email Sender Reputation

If your sender score is between 0-70, chances are that your emails aren’t getting into your subscribers inboxes. That’s no good, but it’s also not the end of the world. Here’s some things you can do to improve your sender reputation and land in those inboxes:

  1. Clean Your Lists. 

Deleting contacts on your email list may seem like a scary thing to do. But the truth is people who are deleting your emails without opening them aren’t going to buy your product anyway. They only make your sender reputation worse so it’s in your best interest to clear them off your list.

  1. Improve Your Engagement. 

Experiment with different subject lines, from names, and content to get your audience opening, clicking, and responding to your emails.

  1. Archive Disengaged Users.

Use your ESP to indicate which people have not opened your last 25, 50, or 100 emails. Clear these folks off your list.

  1. Don’t Scrape or Buy Email Lists.

When you share email lists with other brands and recipients are not aware that they’ve subscribed to your emails as well, it can lead to your emails being marked as spam. Don’t buy or scrape your lists. 



This is a great example of an email that Framebridge sent to their disengaged subscribers when they were trying to clear their list. 

They were upfront about the situation and asked users if they still wanted to be on their email list. It’s a nice way to give users the option to stay on the list or be unsubscribed.

Start Monitoring Your Email Deliverability Now 

Deliverability is the most important part of your email marketing strategy. Your sender reputation matters! Be sure to monitor your sender score to ensure that your emails make it into your subscribers inboxes.


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