How to Authenticate Email Addresses with Amazon SES to Improve Deliverability

Let’s explore how Amazon SES, SPF, and DKIM can help you improve deliverability through address authentication.

Setting up an email server is the easy part. Maintaining your organization’s reputation isn’t so simple.

Amazon designed its Simple Email Service (SES) for ease of use and maximum reliability. The product development team understands the challenges organizations face in a world rife with scammers, so they actively develop SES not only for internal Amazon use, but also for robust, versatile, and scalable service. By offloading complex infrastructure and administration tasks to Amazon, you’ll save yourself time, money, and the major headaches that go along with complicated SMTP implementations. Let’s take a deep dive into Amazon SES to see how it can help you to develop a maintainable and scalable email program.

How to Authenticate Sender Information with SPF or DKIM

Amazon SES uses the SMTP protocol which doesn’t offer a built-in authentication mechanism. How should an administrator verify beyond any doubt that he or she is properly authorized for access? How do you authenticate with ISPs and Amazon SES that you are the original sender and not an evil spammer who spoofed someone else’s account? If you want your emails delivered to live inboxes, you must authenticate yourself and your domain. You can reliably achieve this by taking advantage of one of the following two authentication mechanisms that ISPs recognize:

  1. Sender Policy Framework (SPF)
  2. DomainKeys Identified Mail (DKIM)

We will discuss these authentication mechanisms and how to best use these standards in Amazon SES.

Sender Policy Framework (SPF) for Email Spoofing Detection

In its simplest form, a Sender Policy Framework (SPF) is a simple email validation system designed to detect email spoofing by providing a mechanism that allows receiving mail exchangers to check that incoming mail. They check that a domain comes from a host who is authorized by that domain’s administrators. The list of authorized sending hosts for a domain is published in the Domain Name System (DNS) records for that domain in a specially-formatted TXT record. Email spam and phishing techniques often use forged “from” addresses, so publishing and checking SPF records can be considered an anti-spam safeguard.

Amazon SES sends the subscriber’s emails from a “Mail-From” domain that Amazon SES owns. Because Amazon owns the domain, senders don’t need to modify their DNS records for their emails to pass SPF authentication.

However, the “Mail From” domain of email sent through Amazon SES is amazonses.com (or a subdomain of that), which is different from the subscribers sending domain.  The reason for this structure is inherent in SPF.  Sender Policy Frameworks function by authenticating the IP address that originated from the SMTP connection to the domain used in the SMTP MAIL-FROM and/or the HELO/EHLO command. The “From” header, which is part of the email message itself, is not covered by SPF validation. Moreover, as the MAIL-FROM domain is an SES domain, which doesn’t match your sending domain, SPF authentication is misaligned for DMARC purposes.

DMARC (Domain-based Message Authentication, Reporting & Conformance) is a standard way of telling ISPs how to handle unauthenticated emails. I encourage you to click the link above and learn a little more about DMARC because it is a powerful security component that will contribute to your growing understanding of how all this complex stuff works together.
Back to the topic at hand. Users must enable Domain Keys Identified Mail signing for their verified domain in order to successfully configure DMARC.

DomainKeys Identified Mail (DKIM)

According to Wikipedia: “DomainKeys Identified Mail (DKIM) is an email authentication method designed to detect email spoofing by providing a mechanism that allows receiving mail exchangers to check that any incoming mail from a domain is authorized by that domain’s administrators.”

In technical terms, DKIM is a technique to authorize a domain to associate its name with an email message through cryptographic authentication. Verification is carried out using the signer’s public key published in the DNS. A valid signature guarantees that some parts of the email (possibly including attachments) have not been modified since the signature was affixed.
Usually, DKIM signatures are not visible to end-users. They are affixed or verified by the infrastructure rather than the message’s authors or recipients. In that respect, DKIM differs from end-to-end digital signatures.” Again, learning more about DomainKeys Identified Mail means building your knowledge base and conceiving a greater understanding of the critical components of eMail security. Click the link and read for a few minutes. You’ll retain some of what you read and when you encounter DKIM and SPF you’ll remember some of the differences and can easily refresh your memory with a quick Google search.

How to Authenticate Email with DKIM in Amazon SES

Amazon SES provides two options to sign your messages using a DKIM signature:

  • One method allows domain configuration so that Amazon SES automatically adds a DKIM signature to every message sent from specified domains.
  • Another option applies your own DKIM signature to any email that you send using the SendRawEmail API. (SendRawEmail is an Amazon service that sends an email message with header and content specified by the client).

As an IT professional, you’ll want to evaluate each situation and resist the natural urge of selecting the easiest option. People won’t notice the first five or six hundred times you do it, but eventually, people will see the pattern.
Easy DKIM for SES
Amazon SES offers DKIM signing capabilities through Easy DKIM. This Amazon SES feature authenticates the integrity of an email message, including its content and headers, and proves to the ISPs that your domain is the authentic owner of the specific emails that you sent. It ensures that you take complete responsibility for the volume and contents of all emails.

Important Points Regarding Easy DKIM:

  • You only need to set up Easy DKIM for the domain you use in your “From” address, not for the domain in a “Return-Path” or “Reply-To” address.
  • Amazon SES has endpoints in multiple AWS regions, and Easy DKIM setup applies to each AWS region separately, you must perform the Easy DKIM setup procedure for each region in which you want to use Easy DKIM.
  • If you set up Easy DKIM for a domain, it will apply to all email addresses in that domain except for email addresses that you individually verified.
    • Individually verified email addresses use separate settings.
  • You should be able to edit the DNS Settings.
  • To prevent DNS providers from appending a DNS name if it is already present in your DNS record (e.g. _amazonses.cloudfactory.com), add a period to the end of the domain name in the DNS record. This will indicate to your DNS provider that the record name is fully qualified. Otherwise, it will end up being a duplication (e.g. _amazonses.cloudfactory.com.cloudfactory.com) and rendered invalid.

Conclusion

Amazon SES is a great solution for developers who need industrial-grade reliability, but you’ll want to make sure you implement the proper authentication mechanisms for ensuring delivery reliability. To learn more about SES and other critical AWS products, sign up with Cloud Academy today for a free 7-day trial subscription to our Professional PLUS plan. Here’s what you’ll get:

  • Video courses led by expert instructors who have acquired every single AWS certification available.
  • Self-test quizzes that help you determine which subjects on which you need to focus.
  • Hands-on labs that put you in a live AWS environment to help you learn by doing. 

Sign Up Now for Your Free 7-Day Trial – Comprehensive AWS Prep

 

Avatar

Written by

Chandan Patra

Cloud Computing and Big Data professional with 10 years of experience in pre-sales, architecture, design, build and troubleshooting with best engineering practices. Specialities: Cloud Computing - AWS, DevOps(Chef), Hadoop Ecosystem, Storm & Kafka, ELK Stack, NoSQL, Java, Spring, Hibernate, Web Service


Related Posts

Valery Calderón Briz
Valery Calderón Briz
— October 22, 2019

How to Go Serverless Like a Pro

So, no servers? Yeah, I checked and there are definitely no servers. Well...the cloud service providers do need servers to host and run the code, but we don’t have to worry about it. Which operating system to use, how and when to run the instances, the scalability, and all the arch...

Read more
  • AWS
  • Lambda
  • Serverless
Avatar
Stuart Scott
— October 16, 2019

AWS Security: Bastion Host, NAT instances and VPC Peering

Effective security requires close control over your data and resources. Bastion hosts, NAT instances, and VPC peering can help you secure your AWS infrastructure. Welcome to part four of my AWS Security overview. In part three, we looked at network security at the subnet level. This ti...

Read more
  • AWS
Avatar
Sudhi Seshachala
— October 9, 2019

Top 13 Amazon Virtual Private Cloud (VPC) Best Practices

Amazon Virtual Private Cloud (VPC) brings a host of advantages to the table, including static private IP addresses, Elastic Network Interfaces, secure bastion host setup, DHCP options, Advanced Network Access Control, predictable internal IP ranges, VPN connectivity, movement of interna...

Read more
  • AWS
  • best practices
  • VPC
Avatar
Stuart Scott
— October 2, 2019

Big Changes to the AWS Certification Exams

With AWS re:Invent 2019 just around the corner, we can expect some early announcements to trickle through with upcoming features and services. However, AWS has just announced some big changes to their certification exams. So what’s changing and what’s new? There is a brand NEW ...

Read more
  • AWS
  • Certifications
Alisha Reyes
Alisha Reyes
— October 1, 2019

New on Cloud Academy: ITIL® 4, Microsoft 365 Tenant, Jenkins, TOGAF® 9.1, and more

At Cloud Academy, we're always striving to make improvements to our training platform. Based on your feedback, we released some new features to help make it easier for you to continue studying. These new features allow you to: Remove content from “Continue Studying” section Disc...

Read more
  • AWS
  • Azure
  • Google Cloud Platform
  • ITIL® 4
  • Jenkins
  • Microsoft 365 Tenant
  • New content
  • Product Feature
  • Python programming
  • TOGAF® 9.1
Avatar
Stuart Scott
— September 27, 2019

AWS Security Groups: Instance Level Security

Instance security requires that you fully understand AWS security groups, along with patching responsibility, key pairs, and various tenancy options. As a precursor to this post, you should have a thorough understanding of the AWS Shared Responsibility Model before moving onto discussi...

Read more
  • AWS
  • instance security
  • Security
  • security groups
Avatar
Jeremy Cook
— September 17, 2019

Cloud Migration Risks & Benefits

If you’re like most businesses, you already have at least one workload running in the cloud. However, that doesn’t mean that cloud migration is right for everyone. While cloud environments are generally scalable, reliable, and highly available, those won’t be the only considerations dri...

Read more
  • AWS
  • Azure
  • Cloud Migration
Joe Nemer
Joe Nemer
— September 12, 2019

Real-Time Application Monitoring with Amazon Kinesis

Amazon Kinesis is a real-time data streaming service that makes it easy to collect, process, and analyze data so you can get quick insights and react as fast as possible to new information.  With Amazon Kinesis you can ingest real-time data such as application logs, website clickstre...

Read more
  • amazon kinesis
  • AWS
  • Stream Analytics
  • Streaming data
Joe Nemer
Joe Nemer
— September 6, 2019

Google Cloud Functions vs. AWS Lambda: The Fight for Serverless Cloud Domination

Serverless computing: What is it and why is it important? A quick background The general concept of serverless computing was introduced to the market by Amazon Web Services (AWS) around 2014 with the release of AWS Lambda. As we know, cloud computing has made it possible for users to ...

Read more
  • AWS
  • Azure
  • Google Cloud Platform
Joe Nemer
Joe Nemer
— September 3, 2019

Google Vision vs. Amazon Rekognition: A Vendor-Neutral Comparison

Google Cloud Vision and Amazon Rekognition offer a broad spectrum of solutions, some of which are comparable in terms of functional details, quality, performance, and costs. This post is a fact-based comparative analysis on Google Vision vs. Amazon Rekognition and will focus on the tech...

Read more
  • Amazon Rekognition
  • AWS
  • Google Cloud Platform
  • Google Vision
Alisha Reyes
Alisha Reyes
— August 30, 2019

New on Cloud Academy: CISSP, AWS, Azure, & DevOps Labs, Python for Beginners, and more…

As Hurricane Dorian intensifies, it looks like Floridians across the entire state might have to hunker down for another big one. If you've gone through a hurricane, you know that preparing for one is no joke. You'll need a survival kit with plenty of water, flashlights, batteries, and n...

Read more
  • AWS
  • Azure
  • Google Cloud Platform
  • New content
  • Product Feature
  • Python programming
Joe Nemer
Joe Nemer
— August 27, 2019

Amazon Route 53: Why You Should Consider DNS Migration

What Amazon Route 53 brings to the DNS table Amazon Route 53 is a highly available and scalable Domain Name System (DNS) service offered by AWS. It is named by the TCP or UDP port 53, which is where DNS server requests are addressed. Like any DNS service, Route 53 handles domain regist...

Read more
  • Amazon
  • AWS
  • Cloud Migration
  • DNS
  • Route 53