DKIM Testing for Agencies

When you manage email for dozens of clients, DKIM problems multiply fast. One misconfigured record can tank a client's campaign. Worse, you might not find out until they're asking why their emails aren't getting delivered.

The Agency Challenge

Agencies face unique email authentication challenges:

Multiple clients, multiple domains: Each client has their own domain with its own DKIM configuration. That's dozens or hundreds of DKIM records to track.

Varying technical access: Some clients give you full DNS access. Others make you submit changes through their IT team. Some have no idea what DNS even is.

Different email stacks: Client A uses Mailchimp, Client B uses HubSpot, Client C uses Klaviyo. Each has different DKIM selectors and setup processes.

Accountability without control: You're responsible for email performance, but you often can't directly fix DNS issues.

How DKIM Testing Helps Agencies

The Agency DKIM Workflow

During Client Onboarding

Regular Maintenance

Weekly: Spot-check a few client domains, especially those with active campaigns.

Monthly: Full audit of all client DKIM records. Look for any that have disappeared or changed.

Before major campaigns: Always verify DKIM for the specific domain you're sending from.

When Things Go Wrong

Client emails going to spam? Check DKIM first:

1. Test the DKIM record for the sending domain
2. Verify the selector matches what the email service uses
3. Check the email headers for DKIM pass/fail results
4. If DKIM is failing, identify whether it's a DNS issue or email service configuration

Managing Multiple Selectors

Most clients end up with multiple DKIM selectors:

When auditing a client, check for all selectors they might be using, not just the ones you set up.

Talking to Clients About DKIM

Some clients will ask what DKIM is and why it matters. Here's how to explain it:

For non-technical clients: "DKIM is like a digital signature that proves your emails are legitimate. Without it, Gmail and other providers might think your emails are spam."

For technical clients: "DKIM adds a cryptographic signature to outgoing emails. Receiving servers verify this signature against a public key in your DNS. It's required by major email providers for bulk sending."

When requesting DNS access: "I need to add a TXT record to your DNS for email authentication. This helps ensure your marketing emails reach the inbox instead of spam."

The Full Email Authentication Stack

For client email deliverability, DKIM is one of three essential configurations:

SPF: Authorizes which servers can send email for the domain. Check at spfrecordcheck.com.

DKIM: Adds cryptographic signatures to verify email authenticity.

DMARC: Sets policy for how failures should be handled. Check at dmarcrecordchecker.com.

All three should be configured for every client. When onboarding a new client, audit all three.

Scaling Agency Email Management

As your agency grows, manual DKIM checks become unsustainable. You need:

• Automated monitoring: Get alerts when a client's DKIM breaks instead of finding out when campaigns fail
• Centralized dashboard: See all clients' email authentication status in one place
• Historical tracking: Know when configurations changed so you can correlate with deliverability issues

Monitor Your DKIM Records

Checking once is good. Monitoring continuously is better. The Email Deliverability Suite watches your SPF, DKIM, DMARC, and MX records daily and alerts you when something breaks.