Email Authentication Changes: Are Your Agency’s Emails at Risk?

As of 5th May 2025, Microsoft has started enforcing stricter email authentication rules for bulk senders reaching Outlook.com, Hotmail.com, and Live.com addresses.

Following similar steps taken by Google and Yahoo last year, these changes represent a significant toward tighter email security across the industry.

Essential Requirements for Bulk Email Senders

If your agency sends over 5,000 emails per day, it’s crucial to check you have the following configurations in place:

• SPF (Sender Policy Framework): This allows only authorised servers to send emails on your behalf, protecting your domain from misuse.

• DKIM (DomainKeys Identified Mail): Adds a digital signature to each email, proving authenticity to the receiving server.

• DMARC (Domain-based Message Authentication, Reporting & Conformance): Establishes a clear policy (at minimum p=none) guiding providers on handling unauthenticated emails.

Failing to meet these standards could mean your emails won’t just land in spam but could be completely rejected

Impact on Popular Email Platforms

Agencies commonly rely on platforms like Mailchimp, HubSpot, and Campaign Monitor for bulk emailing.

To maintain high deliverability, you need to ensure your domain’s DNS records are accurately set up to meet these new authentication requirements.

Incorrect configurations or outdated settings will significantly affect your email reach and client communications.

Why is Email Authentication Vital for Your Agency?

Without the correct authentication in place, here’s what you risk:

• Reduced Deliverability: Many of your emails won’t even reach inboxes.

• Reputational Damage: Frequent email rejections and spam flags can severely harm your domain's reputation.

• Loss of Client Trust: Reliable email communication underpins client relationships. Disruptions can lead to frustration and lost business.

How Can You Prepare?

Ensure your agency navigates these changes smoothly by:

• Setting up and verifying SPF, DKIM, and DMARC records.

• Aligning your email domain effectively with marketing platforms.

• Proactively monitoring email systems to maintain consistent deliverability.

If you’re uncertain about your current configuration or need professional assistance to ensure compliance with these changes, Cubit Technology is here to support your agency.