Want to understand email deliverability?

Email deliverability represents the percentage of total emails you send that successfully reach the recipients’ inbox and don’t get caught in spam filters.

In this article, I’ll describe everything you need to know about email deliverability. I’ll discuss what it means, why email inbox placement matters, the factors that affect it, and how you can easily improve email deliverability.

This Article Contains:

(Click on a link to jump to the specific section.)

• What Is Email Deliverability?
• Why Does Email Deliverability Matter?
• How Do You Boost Email Deliverability?
• What Is a Good Email Deliverability Rate?
• What Affects Email Deliverability?

Let’s jump right into it.

What Is Email Deliverability?

Email deliverability is your ability to send emails that reach a recipient’s inbox. It’s a standard email performance metric used to evaluate email marketing effectiveness.

To understand it better, let me ask you something:

What’s your most important goal as an email marketer?

It’s probably to send relevant content to subscribers in hopes of converting them into customers, right?

Now, let’s say you spent a lot of time creating a subscriber list from the ground up. And you spent hours creating engaging content for your audience.

However, if your emails don’t reach your customer’s inbox after everything, all that effort would’ve been for nothing!

That’s one reason email deliverability is always one of the most important factors to consider — especially when comparing different email marketing software, SMTP service providers, and email API services.

Wait, what’s SMTP and email API?

An SMTP (Simple Mail Transfer Protocol) service lets you bypass the sending limits of your email service provider (ESP).

For example, a regular Gmail account has a sending limit of up to 500 emails/day. However, with an SMTP service provider, you can send unlimited emails from Gmail without getting your account suspended.

To know more about SMTP, read my ultimate guide.

On the other hand, an email API service provider lets you access the capabilities of an email marketing tool directly from your website, web app, or mobile application.

Why Does Email Deliverability Matter?

The most obvious importance of deliverability is that your emails avoid the spam folder. If your recipients don’t even receive an email, there’s no point in talking about subscriber engagement.

But there’s more.

A good deliverability rate is also helpful for your reputation as a sender. Conversely, if too many of your emails trigger spam filters, this damages your sender score, leading even more spam filters to block your emails. This becomes a vicious cycle of diminishing deliverability scores.

Since email deliverability is vital to your email marketing strategy, it’s important to evaluate your email deliverability level continuously.

How Do You Measure Email Deliverability?

The email deliverability rate represents the percentage of sent emails that have successfully reached the recipients’ inbox.

To calculate it, take the ratio of the total number of emails received in inboxes to the total number of emails sent, and multiply it by 100.

Email deliverability = (Total number of emails placed in inbox / Total number of emails sent) * 100

However, to determine your email deliverability or inbox placement rate, you first need to know the actual number of emails that end up in your recipient’s inbox.

And that’s where an email marketing tool like GMass comes in handy.

What’s GMass?

GMass is an easy-to-use, robust email marketing tool that works right inside Gmail.

Its superior outreach capabilities and features for personalizing mass email content make it a popular tool used by employees of global powerhouses like Google, Uber, Twitter, and LinkedIn.

It’s also perfect for small businesses, churches, solopreneurs, and pretty much anyone else who uses Gmail!

How does GMass help measure email deliverability?

GMass’ advanced analytics auto-generates a Campaign Report each time you send an email campaign.

It tracks several core email engagement metrics, like:

• Total recipients: total number of email addresses to which the campaign is sent
• Bounces: total number of emails returned as undelivered because the addresses were invalid
• Unique opens: total number of unique email addresses that opened your email
• Didn’t open: total number of email IDs that didn’t open the email
• Replies: total number of subscribers who replied to the email
• Unsubscribers: total number of users who clicked the unsubscribe link in the email
• Blocks: total number of email addresses that came back undelivered because the addresses rejected your email as spam
• Rejections because Gmail account is over its limit: total number of emails that were undelivered because Gmail restricted your account’s sending ability

You can quickly calculate email deliverability as follows:

Email deliverability = (Total Recipients – Blocks – Bounces) / Total Recipients

The report offers a comprehensive outlook on the campaign’s performance, showing you everything — from the number of emails opened to the total number of bounced emails.

But that’s not all!

GMass checks your SPF record before you send a campaign to make sure it’s not missing or incorrect.

GMass’ “Inbox, Spam, or Promotions” email delivery tester lets you check whether your emails are reaching the inbox, spam, or promotions folder. The tool helps you see where your own (or everyone else’s) emails are landing.

Read my article on using the “Inbox, Spam or Promotions” tool for more info.

Moreover, my free Domain Deliverability Statistics Tool helps you find out the delivery statistics and bounce codes for any domain, like Gmail or Yahoo. Search for any domain name, and discover the send, open rates, and bounce rates across any time range.

To know more, read my article on the Domain Deliverability Statistics tool.

How Do You Boost Email Deliverability?

Sure, high email deliverability is essential.

But how do you increase it?

Here are some smart techniques that will help improve your email deliverability and reach more customers:

1. Maintain a Clean Mailing List

A clean mailing list helps you minimize your bounce rate.

Generally, a mailing list is clean as long as it doesn’t include:

• Spam trap addresses.
• Non-existent users.
• Inactive subscribers.

That’s why it’s important to remove such list entries and perform regular subscriber list segmentation.

How does GMass help here?

When a recipient unsubscribes from your mailing list, their email address is automatically moved from your mailing list to the GMass account’s Unsubscribe list.

Additionally, with GMass, you can build mailing lists right inside Gmail.

Simply use the Email List Builder feature to find email IDs deep within your Gmail account.

Here’s how to use the feature:

• Search for a particular keyword in your Gmail account’s search bar.
• GMass will display a list of everyone who has mentioned that term in their emails to you; then click on the Build Email List button to select them all.
• GMass auto-builds an email list using the IDs found in your search list.
• After that, a Compose window is displayed that contains those recipients in the To field.
• You can now send campaigns to this mailing list.

Once you’ve created a send list, GMass auto-saves it so that you can easily resend campaigns to the same set of people anytime.

To learn more, read my article on how to build an email list from your Gmail account.

2. Send Email Campaigns at the Right Frequency

When sending out email campaigns, being regular is a good thing, but being far too frequent can be harmful.

Why?

If you’re someone who sends out bulk email campaigns or lots of transactional emails in bursts, you can expect your Internet Service Provider (ISP) to be strict with you.

ISPs view sudden fluctuations in sending volume with suspicion and can start restricting your email deliverability.

That’s why consistent email-sending frequency and volume is important to improve your deliverability rates and maintain a good sender reputation.

How does GMass help here?

GMass allows you to phase out spikes in your email sending volume by providing an option to increase the delay between sent emails to anywhere between 5-90 seconds.

Additionally, you can use GMass’ powerful email scheduling feature to schedule emails in advance. This way, you can send out campaigns at the right frequency without ticking off your provider.

3. Have a Good Sender Reputation

A sending domain name or IP address with a good sender reputation will generally have better email deliverability.

Sender reputation scores are calculated by ISPs to determine how much the user can be trusted not to send spam. If your domain or IP address has a high sender reputation score, ISPs will assume that your emails don’t contain spam and place your emails in the subscriber’s inbox.

If you’re sending emails from an IP with a poor reputation, your emails run the risk of not getting delivered to the inbox.

How does GMass help here?

GMass solves this by sending all emails from the users’ Gmail accounts — and Gmail’s IP addresses happen to have the best sending reputation globally.

Besides, features like the GMass Spam Solver helps you tweak your emails until they hit the inbox. Modify the subject line and headers, take out images, turn off the tracking domain, and more to ensure you’ve done everything to maximize the deliverability.

4. Set Up Security Protocols

Using security protocols like SPF, DKIM, and DMARC when sending emails increases your reputation when vetted by a mail server.

What are SPF, DKIM, and DMARC?

SPF (Sender Policy Framework) is a security standard used to define which IP addresses can send emails from a specified domain. The allowed IP addresses are listed within an SPF record.

DKIM (DomainKeys Identified Mail) is another email authentication method used to verify that an email from the sender was not forged and that no one has tampered with it.

DMARC (Domain-based Message Authentication, Reporting, and Conformance) is a security policy that checks whether an email is protected by SPF and DKIM and reports back to the sender if both security protocols were to fail.

How does GMass help here?

As you’re sending emails from your Gmail or G Suite account when using GMass, your emails are automatically SPF and DKIM compliant.

What Is a Good Email Deliverability Rate?

Let’s say the email deliverability rate of your campaign is 65%.

Is that a good or bad number?

You want a high deliverability rate, but what’s a reasonable benchmark for good email deliverability?

In 2019, the average deliverability rate was around 80%. This figure differs according to context, with deliverability rates for government websites, retail, SaaS, and blogs varying greatly.

With a service like GMass in your arsenal, you can be much more optimistic and generally attain email deliverability rates over 95%.

What Affects Email Deliverability?

If everyone knows that high email deliverability is desirable, why do emails fail to hit the inbox? What makes emails hard-bounce in the first place?

Here’s a close look at the factors that generally result in an email deliverability issue:

A. Low Sender Reputation

The most critical parameter in ensuring successful email inbox placement is probably your sender reputation.

Sender reputation represents the trustworthiness of the IP address (IP reputation) and domain (domain reputation) used to send out campaigns. ISPs may reject any emails from an email sender whose reputation falls below a certain sender score.

Most inbox provider services also check for security protocols like SPF, DKIM, and DMARC when filtering emails. These are security mechanisms used to prevent a malicious sender or spammer from sending emails on your behalf.

B. Poor Mailing List Quality

When running bulk email campaigns, you don’t send out each email individually. You maintain a subscriber or mailing list and send out bulk emails trying to reach all those addresses.

Maintaining a subscriber list is an example of permission marketing — where the audience is given a choice to opt-in to marketing emails.

However, there are a few problems that can arise with subscriber lists that aren’t updated regularly, such as:

• Spam traps used by ISPs to mimic normal email addresses and lure cold campaign senders.
• Emails being sent to addresses that don’t exist, causing your bounce rate to spike and raising flags with mailbox providers.
• Recipients reporting your unwelcome emails as spam.

Not only do these push you to the edges of a bad reputation, but ISPs and mailbox providers can also use this feedback to limit your campaign reach.

C. Lack of Engagement

A significant problem with permission marketing is that subscribers might grow unresponsive over time. This can happen when the email content you send no longer feels relevant to them.

When the number of emails opened, clicked, replied to by certain users drops, ISPs will interpret your messages as spam emails that are irrelevant and pointless.

Based on these cues, ISPs will want to limit your inbox placement even further, causing your engagement rates to go down.

D. Being Blacklisted

Getting blacklisted is every email marketer’s nightmare.

Blacklists are used by ISPs and mailbox providers to avoid spammy emails from getting to recipients. The lists contain IP addresses and domains known to send spam, and they automatically get filtered out by a spam filter.

This usually arises as a consequence of high spam complaints from accounts that didn’t willingly subscribe to your email program.

E. Difficulty in Unsubscribing

Customers unsubscribing from your mailing list lead to weaker outreach and lower conversions.

So why not make it difficult to unsubscribe and have no unsubscribe links within your emails?

After all, if people can’t unsubscribe, you still get to maintain your reach, right?

While that may sound like a viable solution, it does more harm than good in the long run.

You don’t want to force your customers to stay by not offering them a chance to leave.

If you did, here’s how it would play out:

• A customer who isn’t interested in your content wants to unsubscribe.
• There’s no easy way to unsubscribe, so the customer is forced to stay.
• Your customer keeps receiving emails from your bulk email campaign and starts getting annoyed.
• Without a convenient way to opt-out, the customer is compelled to report your address as spam.

When enough spam complaints are stacked up, the high complaint rate massively reduces the chances of your emails getting placed in subscribers inboxes.

Conclusion

Email deliverability is an important metric to consider when evaluating email marketing effectiveness.

Some mailbox providers allow you to measure email delivery, which is the percentage of sent emails that were not rejected by the mailbox provider or ISP. However, to measure the actual email deliverability rate, you need an email marketing tool like GMass.

With GMass, you can maintain a clean email list, manage phased email sending, build a good sender reputation, and be SPF and DKIM compliant automatically. GMass also comes with tons of other useful email marketing and marketing automation features to enhance your campaigns.

So why not sign up for GMass today and immediately skyrocket your email deliverability?

Ajay Goel

Ajay is the founder of GMass and has been developing email sending software for 20 years.

twitter.com/PartTimeSnob

Looking for the best email validation API?

Sending emails to the wrong email IDs can lead to high bounce rates and low deliverability, ultimately damaging your sender reputation. To avoid this, an email validation API helps you identify and remove inauthentic email addresses from your mailing list.

In this article, I’ll highlight the top 7 email validation APIs along with their features, pricing, and ratings.

This Article Contains:

(Click on the links below to jump to a specific section)

• What Is Email Validation API?
• Top 7 Email Validation API Tools
  • SendGrid Validation API
  • Mailgun Email Validation
  • ZeroBounce
  • DeBounce
  • NeverBounce
  • Clearout
  • Hunter
• The 4 Benefits of Validating Emails

Let’s jump right into it.

What Is Email Validation API?

Email validation is the process of identifying incorrect email addresses from an email list.

An email validation API (also called email verification API) is a tool that automatically checks your mailing list for mistyped email addresses, domains (Gmail, Yahoo, Hotmail, etc.), or disposable email IDs to ensure deliverability.

What’s a disposable email address?

A disposable email address (or a fake ID) is a temporary email ID that expires after a certain time period.

People create and use disposable emails to avoid spammers and phishers when visiting blogs and websites that require them to fill in marketing forms or subscriptions to continue browsing.

Emails sent to these addresses go unnoticed or don’t get delivered at all — affecting your deliverability and sender reputation.

How Does Email Verification Work?

Each email address is systematically analyzed using a variety of factors to verify it.

Here’s a quick look at these stages:

Note: If you’re familiar with the email verification process, skip ahead to the seven best email validation API tools section.

1. Syntax Check

All email addresses follow a particular syntax standardized by the IETF (Internet Engineering Task Force) and RFC (Request for Comments).

An email verifier identifies email addresses that don’t correspond with these standards and removes them from the mailing list.

It usually checks:

• The email prefix (sequence of letters, numbers, and symbols before the “@” sign).
• Email domain (email service provider’s name) that comes after the “@” sign. For example, gmail.com.

An example of an incorrect email address syntax is xyz#[email protected].

2. Address Name Detection

This step detects and flags email names that are role-based or suspicious, as they affect deliverability due to blacklisting: info@, admin@, [email protected], etc., are examples of such email names.

3. DEA Detection

DEA detection identifies and removes disposable email addresses (DEA), which are usually temporarily used by people for signups and subscriptions to avoid spam emails.

4. Spam Trap Detection

Spam traps are fraud management tools disguised as email addresses. They are created by major ISPs (Internet Service Providers) to identify spammers and block them.

If you send email marketing campaigns to these addresses, they will be marked as spam — which affects your sender reputation.

To prevent this from happening to you, email verifiers help remove spam traps from your email list.

5. DNSBL and URI DNSBL Check

An email checker runs your email through a DNSBL (DNS-based blackhole list) and URI (Uniform Resource Identifier).

DNSBL is a list of IP addresses used for spamming, while URI DNSBL is a list of domain names found only in spam email bodies.

6. MX Record Lookup

Checks and verifies the MX records of an email address to identify invalid domains.

MX (mail exchange) records are resource records within the DNS (Domain Name System) that clarify which mail servers accept emails from a domain and which don’t.

When the verifier identifies an invalid domain, it removes that particular email address from your email list.

7. Active Mailbox Check

An email verifier also sends ping requests to an email address’ server to verify whether it’s active. Once the request is received and responded to, it recognizes the mailbox as authentic and active.

Top 7 Email Validation API Tools

Here are the best email validation API tools that help you validate email addresses.

1. SendGrid Validation API

Twilio’s SendGrid is an excellent cloud-based email marketing platform that helps you send massive marketing campaigns across the world.

To use its API endpoint, all you need to do is generate an API key from its settings. Once you get the key, the Email Validation API dashboard will automatically appear in the SendGrid UI.

Check out my detailed SendGrid review to know more.

SendGrid Validation API Key Features

• Offers real-time email address verification using machine learning
• Identifies inactive, temporary, fake, and shared email addresses
• Connects to lead capture forms to avoid email address typos
• Provides risk/validity scores of email addresses
• Helps test inbox rendering to see how an email appears across several mailbox providers and devices

SendGrid Validation API Email List Format

(This is how you can upload and download the data about the emails you’ve submitted for verification)

• Upload: CSV format
• Download: CSV format

SendGrid Pricing

SendGrid’s Email Validation API is available in its Pro and Premier Plans only.

Starting at $89.95/month, the Pro plan offers 2,500 email validations.

SendGrid Ratings

• • G2: 4.1/5 (240+ reviews)
  • Capterra: 4.3/5 (440+ reviews)

2. Mailgun Email Validation

Read my in-depth Mailgun Review to know more about the tool.

Mailgun Email Validation Key Features

• Verifies emails at the point of capture (submission) via its Real-Time Email Validation API
• Automatically tracks bounce rates, unsubscribe rates, and hard bounces via webhooks
• Quickly identifies and removes bad email addresses from email lists through the Bulk List Validation Tool
• Follows both RFC standards and multiple ESP (email service provider) syntax constraints
• Reporting Dashboard provides hourly and daily tracking of validation API usage, types of API calls made, etc.

Mailgun Email Validation Email List Format

Here are the formats to upload and download email lists for verification:

• Upload: CSV, JSON format
• Download: CSV and JSON format

Mailgun Pricing

Mailgun’s email validation API is available with its paid plans, starting at $35/month.

Mailgun Ratings

• G2: 4.5/5 (230+ reviews)
• Capterra: 4.5/5 (90+ reviews)

3. ZeroBounce

ZeroBounce can help you by easily verifying email addresses and IP addresses.

ZeroBounce Key Features

• Removes invalid emails, spam traps, and email addresses with invalid domains, etc.
• Provides activity level scoring for every email address in a list of emails
• The email list scrubbing system offers additional lead information like full names, gender, and geolocation data.
• Offers APIs with SDK (Software Development Kits), which are compatible with Java, PHP, Python, etc., to automate the email collection process
• Integrates with multiple other platforms like Asana, Gmail, and Facebook

ZeroBounce Email List Format

Here’s how you can upload and download your mail lists for verification in ZeroBounce:

• Upload: CSV, .txt, .xlsx, .xls
• Download: CSV

ZeroBounce Pricing

ZeroBounce comes with a Freemium plan that includes 100 credits/month (email address validations) and 18 validation tools (like Spam Trap and Abuse Email Verifier, A.I. Email Scoring, etc.)

The paid plan starts at $15/month and offers 2,000 credits/month.

ZeroBounce Ratings

• G2: 4.6/5 (60+ reviews)
• Capterra: 4.7/5 (350+ reviews)

4. DeBounce

DeBounce’s email verification service even allows you to connect your DeBounce account with Sendinblue, WordPress, and Moosend for bulk email verification.

DeBounce Key Features

• Identifies disposable emails, catch-all domains, and syntax errors
• Locates and removes duplicate email addresses from email lists
• Offers anti-greylisting technology to safeguard emails from getting spammed by any mail transfer agent (MTA)
• Can easily upload email lists directly from your computer or ESP (email service provider)
• Allows team members to use DeBounce from a single team account

DeBounce List Format

Here are the formats in which you can upload and download email lists in DeBounce for verification:

• Upload: TXT, CSV format
• Download: Offers multiple export and download format options

DeBounce Pricing

DeBounce has pay-as-you-go pricing plans where you only pay for the number of email verifications you require.

The starting price is $10 for 5,000 verifications, and new users get 100 credits for free.

DeBounce Ratings

• G2: 4.5/5 (80+ reviews)
• Capterra: 4.7/5 (120+ reviews)

5. NeverBounce

NeverBounce is an excellent email verification tool that cleans up long email lists in a jiffy.

NeverBounce Key Features

• The validation API helps you create custom integrations to add email verification to your own apps and software.
• Can add its product, Verify, to your lead pages, query forms, etc., to validate emails in real time
• Provides API wrappers like PHP, .NET, Ruby, and NodeJS — giving developers full control over creating API integrations from scratch
• Integrates with multiple CRMs and runs automated email list cleaning via its product, Sync.

NeverBounce List Format

Here’s how you can upload and download email lists in NeverBounce:

• Upload: CSV format
• Download: CSV format

NeverBounce Pricing

NeverBounce follows a pay-for-what-you-use pricing model where you only pay for the number of emails you verify. For up to 10,000 emails, the cost per email verification is $0.008.

NeverBounce Ratings

• G2: 4.5/5 (90+ reviews)
• Capterra: 4.5/5 (18+ reviews)

6. Clearout

Clearout Key Features

• Identifies and removes duplicate emails, catch-all email addresses, and erroneous syntaxes from your lists
• Runs DNSBL and URI DNSBL checks to remove spam traps
• Automatically corrects typos in email addresses
• Verifies domains, MX records, free email accounts, SMTP servers, etc.
• Secures the entire email validation process via SSL encryption

Clearout List Format

Here are the formats for uploading and downloading your email lists in Clearout:

• Upload: CSV and .xlsx formats
• Download: CSV format

Clearout Pricing

Clearout offers a pay-as-you-go price structure for one-time use and a monthly subscription for regular users.

In the pay-as-you-go plan, you pay for the number of email validations (credits) you need — for up to 9,999 email validations, you pay $0.0050/email validation.

Its monthly subscription plan starts at $20/month and offers 5,000 credits.

Clearout Ratings

• G2: 4.8/5 (32+ reviews)
• Capterra: 4.8/5 (60+ reviews)

7. Hunter

Hunter offers email verification; however, it doesn’t provide many native integrations.

Hunter Key Features

• Works both as an email finder and an email verifier
• Offers multi-level validations that include SMTP checks and domain information verification
• Provides detailed validation data including a confidence score to show whether an email address is deliverable or undeliverable
• Has a Google Sheets add-on to help you instantly verify emails from your Google Sheets email list

Hunter List Format

Here’s how you can upload and download email lists in Hunter:

• Upload: CSV, .txt formats
• Download: CSV, .txt formats

Hunter Pricing

Hunter offers a free monthly plan of 50 email verifications and domain searches. Its paid plan starts at $49/month and provides 500 verifications.

Hunter Ratings

• G2: 4.3/5 (300+ reviews)
• Capterra: 4.6/5 (400+ reviews)

The 4 Benefits of Validating Emails

Here are four key reasons why email validation is a necessary step in email marketing:

1. Boosts Deliverability and Engagement Rates

Email validation helps you send emails to authentic customers to enjoy high deliverability, engagement, and sender reputation. By removing temporary email addresses, spam traps, and catch-all email accounts, you’ll be dealing with a clean email list.

2. Prevents Hard Bounces

Hard bounces are emails that remain undelivered because you sent them to invalid email addresses. As email verification refines your email list and includes only valid email addresses, it reduces the risk of hard bounces.

3. Helps Choose Better Email Sourcing Method

Verification helps you sort through all the emails you receive from various sources. As a validation API highlights invalid emails, you can compare how many came from each source — such as your web form, sign-up form, or landing page, etc.

This way, you can analyze and fine-tune your email collection process — helping you acquire more valid email addresses than invalid ones.

4. Helps Keep Your Email List Updated

Email addresses of leads and subscribers don’t stay the same forever — an email ID that’s valid today may not be so a year from now. Email verification helps keep your email list up-to-date, ensuring that you always send emails only to existing and authentic email addresses.

Final Thoughts

With an in-depth verification process, email validation APIs not only help you maintain a clean email list, but also they boost your email deliverability and sending reputation.

Check out the tools I’ve covered here to see what email verification API works best for you. Once you’ve found the right tool, say goodbye to spam traps, fake email IDs, and inactive mailboxes!

Ajay Goel

Ajay is the founder of GMass and has been developing email sending software for 20 years.

twitter.com/PartTimeSnob