DKIM Authentication for AI-Powered Email Campaigns

Question

Pulumi · Accepted Answer

DomainKeys Identified Mail (DKIM) is an email authentication method that businesses use to combat email spoofing. DKIM enables an organization to take responsibility for a message while it's in transit. It provides a cryptographic signature that verifies that the email message wasn't altered after it was sent and that it's authorized by the domain owner.

When setting up DKIM for email campaigns, you often need to perform the following tasks:
1. Generate a DKIM key pair (public and private keys).
2. Publish the DKIM public key in your DNS records.
3. Configure your email sending service to sign emails with the DKIM private key.

Pulumi offers resources in its AWS provider package that enable you to automate part of this process. Specifically, you can use the `aws.ses.DomainDkim` and `aws.sesv2.EmailIdentity` resources to configure DKIM for a domain in Amazon Simple Email Service (SES), AWS's email sending service.

Below is a Pulumi program written in Python that sets up DKIM authentication for a domain using AWS SES. This will prepare your domain for sending DKIM-signed emails:

```python
import pulumi
import pulumi_aws as aws

# Replace 'your-domain.com' with your actual domain.
domain_name = 'your-domain.com'

# Set up a domain identity for your domain in SES. This represents the domain you will be sending emails from.
domain_identity = aws.ses.DomainIdentity('domainIdentity', domain=domain_name)

# Generate DKIM tokens for the domain identity. These tokens are used to create CNAME records in your DNS settings.
dkim = aws.ses.DomainDkim('domainDKIM', domain=domain_identity.id)

# Output the DKIM DNS records. You'll have to add these to your DNS settings manually or with additional Pulumi DNS resources.
dkim_tokens = []
for i, token in enumerate(dkim.dkim_tokens):
    record_name = f"{token}._domainkey.{domain_name}"
    dkim_tokens.append(pulumi.Output.all(domain_name, token).apply(
        lambda args: aws.route53.Record(f"dkimRecord-{i}",
                                        name=record_name,
                                        type="CNAME",
                                        records=[f"{args[1]}.dkim.amazonses.com"],
                                        ttl=600,
                                        zone_id=your_hosted_zone_id)))

pulumi.export('domain_identity_verification_record', domain_identity.verification_token.apply(
    lambda token: f"{domain_name}. IN TXT {token}"))
pulumi.export('dkim_dns_records', dkim_tokens)
```

In this program, we first declare a domain identity with AWS SES using the `aws.ses.DomainIdentity` resource, which serves as a verification that you own the domain you're setting up DKIM for. AWS SES requires you to verify that you own the domain to prevent unauthorized use of the domain.

We then use the `aws.ses.DomainDkim` resource to enable DKIM for the domain by creating the necessary tokens which are part of the DKIM authentication process.

The `dkim_tokens` list will store the DNS CNAME records that you need to add to your DNS provider's configuration. These records associate the DKIM tokens with the AWS SES DKIM endpoints. This step is what allows receiving email servers to verify that emails are indeed coming from your domain and that they have not been tampered with.

The program outputs include the verification record that needs to be added to your DNS settings to verify domain ownership with AWS SES and the DKIM tokens that you must add as CNAME records in your DNS settings.

Please note that to fully automate the DNS record creation, you need to manage your domain's DNS settings with Pulumi as well using `aws.route53.Record` resources in case of AWS Route 53. The variable `your_hosted_zone_id` needs to be replaced with your actual Route 53 hosted zone ID.

After you run this Pulumi program and add the DNS records it outputs, your emails sent from this domain through AWS SES will be signed with DKIM, making them more trustworthy in the eyes of other email servers and reducing the chance of your emails being marked as spam.