AWS Messaging & Targeting Blog

Amazon SES – How to set up EasyDKIM for a new domain

What is email authentication and why is it important?

Amazon Simple Email Service (SES) lets you reach customers confidently without an on-premises Simple Mail Transfer Protocol (SMTP) system. Amazon SES provides built-in support for email authentication protocols, including DKIM, SPF, and DMARC, which help improve the deliverability and authenticity of outgoing emails.

Email authentication is the process of verifying the authenticity of an email message to ensure that it is sent from a legitimate source and has not been tampered with during transmission. Email authentication methods use cryptographic techniques to add digital signatures or authentication headers to outgoing emails, which can be verified by email receivers to confirm the legitimacy of the email.

Email authentication helps establish a sender’s reputation as a trusted sender. Additionally, when email receivers can verify that emails are legitimately sent from a sender’s domain using authentication methods, it also helps establish the sender’s reputation as a trusted sender. Email authentication involves one or more technical processes used by mail systems (sending and receiving) that make certain key information in an email message verifiable. Email authentication generates signals about the email, which can be utilized in decision-making processes related to spam filtering and other email handling tasks.

There are currently two widely used email authentication mechanisms – SPF (Sender Policy Framework) and DKIM (DomainKeys Identified Mail). They provide information that the receiving domain can use to verify that the sending of the message was authorized in some way by the sending domain. DKIM can also help determine that the content was not altered in transit. And the DMARC (Domain-based Message Authentication, Reporting and Conformance) protocol allows sending domains to publish verifiable policies that can help receiving domains decide how best to handle messages that fail authentication by SPF and DKIM.

Email authentication protocols:

  1. SPF (Sender Policy Framework): SPF is an email authentication protocol that checks which IP addresses are authorized to send mail on behalf of the originating domain. Domain owners use SPF to tell email providers which servers are allowed to send email from their domains. This is an email validation standard that’s designed to prevent email spoofing.
  2. DKIM (DomainKeys Identified Mail): DKIM is an email authentication protocol that allows a domain to attach its identifier to a message. This asserts some level of responsibility or involvement with the message. A sequence of messages signed with the same domain name is assumed to provide a reliable base of information about mail associated with the domain name’s owner, which may feed into an evaluation of the domain’s “reputation”. It uses public-key cryptography to sign an email with a private key. Recipient servers can then use a public key published to a domain’s DNS to verify that parts of the emails have not been modified during the transit.
  3. DMARC (Domain-based Message Authentication, Reporting and Conformance): is an email authentication protocol that uses Sender Policy Framework (SPF) and DomainKeys Identified Mail (DKIM) to detect email spoofing. In order to comply with DMARC, messages must be authenticated through either SPF or DKIM, or both.

Let us dive deep into DKIM in this blog. Amazon SES provides three options for signing your messages using a DKIM signature:

  1. Easy DKIM: To set up a sending identity so that Amazon SES generates a public-private key pair and automatically adds a DKIM signature to every message that you send from that identity.
  2. BYODKIM (Bring Your Own DKIM): To provide your own public-private key pair for so SES adds a DKIM signature to every message that you send from that identity, see Provide your own DKIM authentication token (BYODKIM) in Amazon SES.
  3. Manually add DKIM signature: To add your own DKIM signature to email that you send using the SendRawEmail API, see Manual DKIM signing in Amazon SES.

The purpose of EasyDKIM is to simplify the process of generating DKIM keys, adding DKIM signatures to outgoing emails, and managing DKIM settings, making it easier for users to implement DKIM authentication for their email messages. Using EasyDKIM, Amazon SES aims to improve email deliverability, prevent email fraud and phishing attacks, establish sender reputation, enhance brand reputation, and comply with industry regulations or legal requirements. EasyDKIM doubles as domain verification (simplification) and it eliminates the need for customers to worry about DKIM key rotation (managed automation). By automating and simplifying the DKIM process, EasyDKIM helps users ensure the integrity and authenticity of their email communications, while reducing the risk of fraudulent activities and improving the chances of emails being delivered to recipients’ inboxes.

Setting up Easy DKIM in Amazon SES:

When you set up Easy DKIM for a domain identity, Amazon SES automatically adds a 2048-bit DKIM signature to every email that you send from that identity. You can configure EasyDKIM by using the Amazon SES console, or by using the API.

The procedure in this section is streamlined to just show the steps necessary to configure Easy DKIM on a domain identity that you’ve already created. If you haven’t yet created a domain identity or you want to see all available options for customizing a domain identity, such as using a default configuration set, custom MAIL FROM domain, and tags, see Creating a domain identity. Part of creating an Easy DKIM domain identity is configuring its DKIM-based verification where you will have the choice to either accept the Amazon SES default of 2048 bits, or to override the default by selecting 1024 bits. Steps to set up easyDKIM for a verified identity:

  1. Sign in to the AWS Management Console and open the Amazon SES console at https://console.aws.amazon.com/ses/
  2. In the navigation pane, under Configuration, choose Verified identities.

  3. List of verified identities in SES console

    Verified identities

  4. In the list of identities, choose an identity where the Identity type is Domain.
  5. Under the Authentication tab, in the DomainKeys Identified Mail (DKIM) container, choose Edit.
  6. In the Advanced DKIM settings container, choose the Easy DKIM button in the Identity type field.

  7. Choose EasyDKIM as identity type; RSA_2048_BITT in DKIM signing key length; Check Enabled checkbox under DKIM signatures.

    DKIM settings

  8. In the DKIM signing key length field, choose either RSA_2048_BIT or RSA_1024_BIT.
  9. In the DKIM signatures field, check the Enabled box.
  10. Choose Save changes.
  11. After configuring your domain identity with Easy DKIM, you must complete the verification process with your DNS provider – proceed to Verifying a DKIM domain identity with your DNS provider and follow the DNS authentication procedures for Easy DKIM.

Conclusion:

Email authentication, especially DKIM, is crucial in securing your emails, establishing sender reputation, and improving email deliverability. EasyDKIM provides a simplified and automated way to implement DKIM authentication. It removes the hassles of generating DKIM keys and managing settings, while additionally reducing risks and and enhancing sender authenticity. By following the steps outlined in this blog post, you can easily set up easyDKIM in Amazon SES and start using DKIM authentication for your email campaigns.

About the Author

Vinay Ujjini

Vinay Ujjini is an Amazon Pinpoint and Amazon Simple Email Service Worldwide Principal Specialist Solutions Architect at AWS. He has been solving customer’s omni-channel challenges for over 15 years. He is an avid sports enthusiast and in his spare time, enjoys playing tennis & cricket.