20 Email Deliverability Best Practices You Must Follow in 202017 minutes read

Even after the evolution of many internet messengers and other mediums of sending messages, email communication is staying apart from the whole league and is having a top priority base when it comes to Business Communication. According to recent data of Radicati, 128.8 billion business emails are sent and received every day. Having said that, 81% of SMBs use email as the primary source to communicate with their clients.
But what about Email Deliverability?

Does the sender know if his emails are hitting right in the recipient’s inbox?

Out of 128.8 billion business emails, 14.5 billion emails move to SPAM, and 31 billion emails get bounced every day. As the statistics explain, email deliverability is a significant issue for all sales personnel, email marketers, or any other professional using mass emails reaching out to their prospects. In this article, I shall be explaining every minute detail about the best practices for getting maximum email deliverability.

Table of Contents

  1. What is Email Deliverability?
  2. Why is Email Deliverability important?
  3. Email Deliverability Best Practices
    1. Authentication
    2. Sender Reputation
    3. Email Content
    4. User Engagement
  4. Email Deliverability Testing Tools
  5. Conclusion

What is Email Deliverability?

In simple terms, Email Deliverability is the ability to deliver the email in the recipient’s mailbox. But this is not as simple as the statement looks. There is a lengthy process an email has to go through before reaching the recipient’s inbox. The email has to move through different filters designed by various Email Service Provider, SPAM filters, email body content as well as the recipient itself. When the email passes through all these filters and lands successfully in the recipient’s primary inbox, it is said to be a successful email delivery.

Why is Email Deliverability Important?

Email Deliverability is important for two reasons:

  • Get your conversions done:

Everyone sends their emails with a purpose. They want their users to read the email and take action. But if the email doesn’t get delivered correctly, it will thoroughly affect the end goal. Having said that, if you succeeded in bettering your email deliverability, the conversion rate with gradually increase.  

  • You don’t want to be a spammer: 

No one wants to be a spammer. Everyone wants to enjoy the freedom of reaching directly to the inbox rather than being dumped in the SPAM. But if we don’t follow the best practices of sending mass emails, you will be labeled as a spammer soon. If people start marking you as Spam, it becomes a critical email deliverability issues. 

To maximize the efficiency of an email campaign, you need to get it right from the moment you start creating your plans. Let’s dive deep and understand what all goes into significantly improve your deliverability. 

Email Deliverability Best Practices


As you already know, why email deliverability is so essential, You need to understand best practices of email deliverability to get your emails successfully land in the recipient’s inbox. Below I will be explaining the best practices that should be followed sequentially to get the best email deliverability.

1. Authentication

Every day I come across many mass email senders who are facing the issue with email deliverability. They explain that their new account gets blocked even though they send a mass email to a small list of 100 recipients.

Yeah! It’s true; it happens, the first thing a mass email sender must know is to authenticate their email account. Authenticating your email account is like providing a driving license to it for moving ahead on the road to the receiver. 

There are four types of email authentication required to send mass email without blocking your email account and landing straight to the recipient’s inbox.

  1. SPF
  2. DKIM
  3. DMARC
  4. Custom Domain

i. SPF(Sender Policy Framework)

SPF is an email authentication protocol that allows the admin of the domain to define the list of mailing servers used from the domain. SPF creates a record in your DNS (Domain Name System), which lists down all the servers that are authorized to send emails on behalf of a domain. The record also specifies how recipients are supposed to handle emails that are sent from unauthorized servers.

Whenever a sender sends an email from an SPF authorized domain, the recipient’s ESP checks the SPF authentication and provides a clean chit to the sender’s domain.

ii. DKIM(Domain Keys Identified Mail)

DKIM is another email authentication process designed to detect email spoofing. DKIM provides an identical digital signature with your DNS records, which helps the sender’s ESP to verify that the email it has received it from an authorized source.

Adding the DKIM records in the DNS boosts your email productivity and helps you from staying away from many major email scams.

iii. DMARC(Domain-based Message Authentication, Reporting & Conformance)

DMARC is not a must-have authentication process but a good-to-have an authentication process to improve email deliverability.  

DMARC records use your SPF and DKIM records to assure the receiver’s ESP that no fraudulent activities are associated with the email.

Sometimes the Internet Service Providers also restrict some IP addresses or Domain Servers. In these cases, the DMARC records come to the rescue and make your email go through it.

iv. Custom Domain

Adding a custom domain is a trick to improve email deliverability. Also tracking links in your email body pulls your emails to the SPAM filter because the ESPs usually blacklist the tracking links. Providing a custom domain changes the original tracking domain with your customized domain, which is safe to use and not blacklisted by any email service providers. Usually, proper email automation tools like SalesHandy allows you to add a custom domain to your links to improve your email deliverability.

2. Sender Reputation

Sender Reputation is a score decided by various Email Service Providers according to your domain score and IP address. The more the score, the better is the email deliverability. I am describing all the factors below that helps a sender to increase his Sender Reputation.

i. Warm-up your email account

Although after authentication, you have received a license to drive your emails to the recipient’s inbox. But it’s never suggested to send huge email campaigns from a new email account. You have to start slow and grow gradually. 

If you send a mass email campaign at the first take, your account might come under the vigilance of your email service provider, and this can affect your email deliverability. Sometimes this might end with permanent blocking your account.

You need to start by sending individual emails and create a conversation. You should follow this practice for a few days and gradually increase your number. Email Warmup helps in increasing your sender reputation score and make your account healthy for email campaigns.

ii. Maintain Sending Quota

Although you are allowed to send bulk emails, but should keep track of how many emails you are sending in a day. If you pull out a long list of recipients and start sending emails without keeping a count, your emails might get failed. You should never exceed your email quota. If you exceed your email quota regularly, your email service provider starts keeping an eye on your activities and might get your account blocked temporarily or permanently.

You need to follow the best email deliverability practices by not exceeding the email sending quota.

iii. Stay Aware of Email Blacklists

Email blacklists are the list of IP addresses and domain those are suspected of sending SPAM emails. It is a realtime database that decides which emails are valid and which all are SPAM. 

There are two types of Email Blacklists:

  • Domain Based:

These are the list of domains those who frequently misuse the domain by sending SPAM or doing any phishing activities.

  • IP Address Based:

These are the list of IP addresses or networks which are frequently used to send SPAM contents or abusive contents.

You should continuously check your domain and IP address, If it is blacklisted, you need to start warming up your domain once again and make a fresh start.

iv. Feedback loop

Usually, the email service providers give you a feedback loop to check email deliverability. A feedback loop allows the recipients to report back to the sender. 

When a receiver doesn’t want to get subscribed to a particular mail, he can write a feedback to the sender with the reason. This helps the sender to take a specific action with it. In the long run, the feedback loop helps in email deliverability, and the sender can have a clean list of recipients.

v. Email List should be verified.

Getting a list of recipients is not a difficult task. But it usually happens the email addresses in the recipient list turns out to be an invalid, expired, or fake. So it is always suggested verifying the subscriber list with a verification tool. Verified Email list decreases your bounce rate, increase your email deliverability and also your sender reputation score.

Usually, after verifying your recipient’s list through any tool, it segments your recipient’s list into 3 types: Valid, Risky, and Invalid.

Valid: These are the verified contacts and are safe to send.

Risky: These are the existing contacts but are not safe to send as those accounts lack engagements.

Invalid: These are the non-existing or expired contacts, and we are not suggested to send emails to them. They get bounced for sure.

vi. Stay away from Email Bounces


No one wants their emails to get bounced, but still, it happens to 9% of business emails. Getting your emails bounced is equally said as losing an opportunity after making the efforts. Even further, when a sender’s emails get bounced more frequently, he is more vulnerable to get his account under threat. If a sender is getting too many emails bounced, his account can get deactivated soon.

Usually, 2 types of bounces should be known by every email sender.

Hard Bounce:

Hard Bounce occurs when your recipient’s email address is not existing, has expired, or the domain is invalid. This is a permanent bounce and you can never send an email to that email address. You need to remove those email addresses from your recipient’s list. 

Soft Bounce:

Soft Bounce occurs if the recipient’s inbox is full, or your email file size is too large or any other temporary issue. These bounces are for a short time duration, but if you are unable to send emails to these email address after multiple tries, you need to remove the recipient from your list.

3. Email Content

The email content is the primary factor that decides whether your email will land in the recipient’s inbox or SPAM. To build the best practice, follow all the points mentioned below to create good content for excellent email deliverability.

i. Subject Line

The subject line is the first thing the recipient sees when they receive the email. 69% of recipients report email as spam based on the subject line. SPAM filters also do the same thing. If the subject line contains spammy keywords or anything that is not relevant to the recipient, then it is more pronto hit the SPAM box either by the SPAM filter or by the recipient. Ultimately this is going to affect your email deliverability.

ii. Spam Triggering Words

It’s crucial to restrict spammy words in both the subject line as well as the email body. Various Email Service Providers include a new spammy keyword in their algorithms to filter your emails. Even a single spammy keyword might affect your email deliverability to a high extreme.

iii. Text to HTML ratio

The visual content produces the best conversion, but you can’t do that at the stack of email deliverability. An email with too much HTML content looks spammy and but at the same time, readers don’t prefer plain text emails. So to have the most suitable balance of both, the best practice is to maintain 60:40 Text to HTML ratio.

iv. Links

Using links in the emails is essential for conversions. However, using too many links in a single email pulls the attention of the ESP and makes your email hit the SPAM folder. It’s very dangerous as it affects your sender reputation score and email deliverability. 

Another reason is adding tracking links in your email. The tracking link is usually blacklisted by various ESPs, which has a direct impact on your email deliverability rate.

v. Personalization

Personalized emails tend to have a 29% more open rate than standard emails. That’s obvious; everyone loves to be addressed personally. Other than that, personalization increases email open rate, which eventually improves your email deliverability and your conversions.

Using an email automation tool like SalesHandy helps the sender to add personalized merge tags. This improves your email deliverability and brings your email goals much closer.


vi. Text Formatting and color

Text formatting plays a crucial role in enhancing user engagement.  As writing a subject line in all CAPs pulls the attention of the spam filters. Its recommended writing as if you are sending a message to your friend. Also, while composing the email, don’t use multiple colors as it is a bad practice; it decreases your successful email deliverability.

4. User Engagement

Even if you use the best email sending deliverability, the receivers will SPAM you if the email content is not relevant to them. So, it is very important to create a User Engagement Platform from your side to get an assured email deliverability. Refer below for the best practices of User Engagement.

i. Segment your Email Lists

Segmenting the email list is one of the best practices to be followed. You need to categorize your recipient list according to the types of prospects. After that, you should send relevant emails to your recipients. This might happen that the email content you send is relevant to a marketer but not to a recruiter. In these cases, a recruiter might SPAM your email, which you don’t want.

It is also suggested to remove recipients from your segmented list if they are not replying to your emails and follow-ups. If your emails are irrelevant, then they might be spamming it. Ultimately you maintain your sender reputation score and improve email deliverability.

ii. Add an unsubscribe link

Adding an unsubscribe link in your email campaign is a must-have thing to stay away from SPAM filters. If the recipient wants to opt-out from your list, he looks for an unsubscribe. If he doesn’t find an unsubscribe button, chances are high to report SPAM. Getting a SPAM count is way more dangerous than getting unsubscribed. An increase in spam rate is going to decrease your email deliverability and domain score directly. Your domain might get blacklisted soon after many recipients mark your email as SPAM.

iii. Use a persuasive subject line

Using a persuasive subject line tempts the customer to open the email and have a look at it. It is a beneficial psychological factor that affects your email deliverability.

Subject lines like “Here’s a Quick Way to start your product selling” or “The PERFECT traffic platform?” creates a temptation in the recipient’s mind and make them read the email.

Deceptive email subject line like adding “FWD:” or “RE:” at the beginning of the subject line forces the sender to mark SPAM even if he reads the content.

iv. Email Seed List

An email seed list is a group of email list that is used to test your email deliverability before running the actual mass email campaign. This particular list contains test email addresses of different email ESPs through which a sender can know all about the vulnerability of his email content towards different ESPs. The email seed list can help a sender to plan accordingly.

Email Deliverability Testing Tools

Before sending a mass email campaign, we need to test email deliverability at every step for knowing the email sender score and your domain health. I am listing some of the important tools that are going to be very helpful to you for email deliverability testing.



Mail-Tester is a free tool to check all the detailed aspects associated with your email content and domain. You need to send an email with your content to an identical email id provided by mail-tester and mail-tester will provide all the details of your email contents and authentications.



Glockapps is a similar tool as Mail-tester but with many advanced features. You can check whether your emails are dropping in the inbox or the SPAM box for different Email Service Providers. With the premium plan of the Glock app, you can do a complete email deliverability test and get a report of email subject line, email body content, Authentications, and blacklists.



Mxtoolbox is a popular tool used by many email marketers to improve their email deliverability. This tool provides all types of tests regarding your domain health and DNS. Mxtoolbox is also used widely for testing the blacklist score as it shows relevant results.

DKIM Validator


DKIM Validator is a straightforward and free tool to check your authentication and improve your email deliverability. With DKIM Validator, you can check if your SPF and DKIM are correctly working or not. Along with that, it can show the SPAM score of your email content via SpamAssassin.



Sendcheckit is a subject line testing tool, which helps you to check the spam score of the subject line and also provides simplified suggestion on how to improve your subject line for better email deliverability.



ISnotSPAM is used to check the SPAM content in your email body. Just send an email to the identical email address provided by ISnotSPAM, and you can see the spam score and all the details about improving your content. It lists down all the checklist that usually gets hit into the spam filter, from the email content side. This is an essential email deliverability tool.


Getting your emails delivered to the right folder of the right person at the right time is nothing less than an achievement. To achieve the best result, it is necessary to use the above pointers every time before sending any mass emails. This will build your sender reputation, increase your domain reputation, and maximum email deliverability.