The Skysnag Blog

Intro to Email Authentication: 2024

October 11, 2023  |  5 min read

What is email authentication?

Email authentication is the process of verifying that an email comes from the sender that it claims to come from. When email servers communicate with one another to exchange email messages, they do this. Email authentication is most commonly used to prevent harmful or fraudulent email uses like phishing and spam.

Benefits of email authentication?

Email authentication provides a number of benefits, including:

  • Reduced spam: Email authentication can help you receive less spam by confirming that an email is from the sender that it claims to be from.
  • Reduced phishing: Because email authentication verifies the sender of an email, it can assist to minimize the incidence of phishing, which occurs when thieves send emails that look to be from a genuine source in order to fool you into giving personal or financial information.
  • Improved deliverability: Using email authentication, you may help ensure that your emails reach your recipients’ inboxes rather than being banned by spam filters.

How does email authentication work?

Email authentication verifies that an email message has not been tampered with and that it truly originates from the sender it claims to originate from. The sender’s email server adds a digital signature to the message when it is transmitted. This signature includes information that can be used to authenticate the message’s validity. When the receiving email server receives the message, it uses the signature information to verify that it is from the sender it claims to be from and that it has not been tampered with.

Both the sender and the recipient of the email must engage in email authentication for it to work. This is why email authentication technological standards are so crucial. They propose a standard approach to setting email authentication rules that any company can use. Email sender authentication gives message recipients some assurance that the message came from the specified source. Understanding how to authenticate email is critical for organizations because it promotes trust and confidence in recipients.

Email authentication relies on basic standards

SPF, DKIM, and DMARC are the most widely used email authentication protocols. Because SMTP, the core protocol for sending email, lacks any authentication techniques, these standards were created to supplement it.

  • SPF: allows senders to specify which IP addresses are allowed to send mail for a specific domain.
  • DKIM: uses an encryption key and a digital signature to ensure that an email message has not been forged or tampered with.
  • DMARC: combines the SPF and DKIM authentication protocols into a single framework, allowing domain owners to specify how an email from their domain should be handled if an authorization test fails.

Most modern email systems accept these email authentication standards, which are a complement to SMTP, the core protocol for sending an email. For implementation, all three of these standards rely on the widely used domain name system (DNS). Sophisticated email senders use email domain authentication as a crucial component of security and deliverability, with DNS acting as the phonebook of the Web, effectively verifying the legitimacy of domains through a rigorous process of research and verification.

Email authentication is essential for any SaaS app

If your SaaS service sends email, as nearly every modern software does, you’ll need to build one or more forms of email authentication to ensure that emails sent from your product are legitimate. Consider it a digital identity card that safeguards your brand, identity, and reputation. One of the most critical measures you can take to protect your app’s reputation is to configure email authentication standards like SPF, DKIM, and DMARC correctly.

What is the reason for this? Email spammers can modify the source address of emails at will and try to get past spam filters and other defenses if there are no systems in place for email authentication. Phishing schemes are similar in that the sender’s address is modified to make it appear as if the communication came from a reputable sender. To tempt readers into clicking through to fake websites where user information such as passwords or account numbers can be taken, cybercriminals regularly send email without authentication and replicate the brand look and feel of banks, social networks, and other well-known entities.

How to Authenticate Your Email in 5 Steps

Email authentication provides assurance to mailbox providers that messages sent by senders are genuine and not delivered by a bad actor. The greater the confidence a mailbox provider has in the communications you submit, the more likely the message will be delivered to the inbox.

Spammers deceive your consumers into giving away their passwords, account details, and other personally identifiable information by appearing to send emails from your domain, a process known as phishing. Not only does this create a negative experience for your customers, but it also reduces general trust in your brand and communications.

While email authentication can be difficult, it’s critical that any web application that sends an email has it at the top of its list of best practices. Here’s how to do it:

Use consistent sender addresses

It’s tempting to have subscribers read a message out of curiosity, but message trust begins with the recipient quickly recognizing the sender as a brand they trust. Changing your recipients’ names and addresses frequently makes them more vulnerable to phishing.

Similarly, avoid utilizing cousin domains or slight variants of your normal brand’s domain, as this erodes trust in your messaging and trains receivers to be more vulnerable to phishing assaults. For example, if your domain is, you should avoid utilizing as a comparable name.

Authenticate your IP addresses with SPF

SPF stands for Sender Policy Framework, and it checks an email sender’s IP address to a list of IP addresses that are allowed to send mail from that domain. The SPF record is a list of permitted IP addresses that is added to a sender’s domain name system (DNS). We take care of the SPF record for senders autonomously.

Configure DKIM signatures for your messages

Skysnag automates DKIM for you, saving you the trouble and time required for manual configuration.

Protect your domain with DMARC authentication

SPF and DKIM must both pass before a DMARC record can be published alongside your DNS records. It also requires that the from address domain and the domain used to authenticate the message match. The DMARC record allows the domain owner to receive forensic reports on rejected messages and possible domain spoofing, as well as tell receiving servers what to do with messages that look to be spoofed (such as block them outright or put them in the spam folder).

Prepare for BIMI

Brand Indicators for Message Identification (BIMI) is a cherry on top of the authentication cake that gives your recipients an even greater inbox trust experience. BIMI will allow senders with a solid sending reputation, DMARC in place and in enforcement, and a published BIMI record to give their brand’s logo in the inbox so that subscribers can immediately and readily recognize their message as trusted.

In terms of authentication, BIMI is the only visual clue a typical email user can use to identify a message’s source and authenticity.


Skysnag automates DMARC, SPF, and DKIM for you, saving you the trouble and time required for manual configuration Our automated domain tools help to monitor every aspect of your email authentication successfully. Skysnag allows you to build trust with your recipients and help prevent your brand from spoofing ultimately leading to happier, more engaged subscribers.

Get started with Skysnag by using this link for a free trial and enforce powerful and effective protection from phishing attacks. 

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