What actually keeps email trustworthy in an era of spoofing, phishing, and AI-powered abuse? Strong authentication.

In this episode of Email After Hours, Guy Hanson sits down with Tom Bartel, SVP of Data Services at Validity and Chair of the M3AAWG Board of Directors, to unpack the latest DMARC updates—and why they matter for every email sender.

From SPF and DKIM to DMARC enforcement and reporting, Tom breaks down the often-confusing world of email authentication into practical terms. Together, Guy and Tom explore how new the DMARC standards improve consistency across mailbox providers, close long-standing security gaps, and help legitimate senders strengthen both deliverability and brand trust.

They also dive into the collaborative process behind internet standards, the role organizations like M3AAWG and the IETF play in shaping the email ecosystem, and why authentication has become one of the clearest signals separating trusted senders from bad actors.

If you’ve ever wondered how mailbox providers determine trust, this episode is essential listening.

What you’ll learn:

What DMARC actually is and how it works alongside SPF and DKIM
What changed in the latest DMARC updates and why those changes matter
How organizations like M3AAWG and the IETF collaborate to evolve email standards
How authentication standards continue to evolve alongside new abuse tactics
What senders should review in their own DMARC setup to stay aligned with modern best practices

…and more!

About Tom Bartel

Tom Bartel is SVP of Data Services at Validity and Chairman of the Board at M3AAWG, with more than 25 years of experience spanning email, data, security, and digital marketing. He works with global brands, ESPs, and major mailbox providers including Microsoft, Yahoo, and Comcast to help organizations navigate messaging trust, sender reputation, email security, and data privacy. Known for his deep expertise in the email ecosystem, Tom brings a unique 360-degree perspective on deliverability, abuse prevention, and the future of trusted digital communication.

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Episode Highlights

[02:08] What M3AAWG does and why collaboration matters
[04:27] DMARC explained In simple terms
[06:19] Why DMARC took years to evolve
[09:47] New DMARC RFCs, tags, and technical updates
[17:24] Reporting changes, sender benefits, and deliverability gains
[23:38] Future DMARC initiatives and helpful resources

Episode Resources:

Tom Bartel on LinkedIn: https://www.linkedin.com/in/barteltom/