Email Deliverability
Mailbox Provider Roundtable: Recapping Microsoft, Gmail, and Yahoo’s Thoughts on New Bulk Sender Requirements
minute read
The email marketing sector wasn’t surprised by Microsoft’s announcement to join Gmail and Yahoo in setting requirements for bulk senders. Yet, it was surprising (and extremely exiting) that these three mailbox providers coordinated across time zones for a roundtable discussion on Validity’s State of Email Live webinar!
Validity’s Guy Hanson led the much-anticipated conversation as thousands of email geeks lit up the Zoom room with lively chatter and thoughtful questions.
While we highly suggest listening to the entire webinar on-demand, here are a few takeaways from the conversation.
Microsoft is thrilled to join Gmail and Yahoo in creating a better inbox
Microsoft’s new requirements (for top-level domains sending over 5,000 messages per day) were a long time coming for Microsoft’s Principal PM Architect Ross Adams. As shared in our previous blog post, the requirements include stronger authentication measures including SPF, DKIM, and a DMARC record of at least p=none.
On May 5th, 2025, Microsoft began enforcing these requirements and rejecting non-compliant senders outright, while providing a bounce code (550; 5.7.515 Access denied, sending domain [SendingDomain] does not meet the required authentication level) and reason for rejection. Adams explained that this upfront rejection is the most direct way notify senders they need to reexamine their program and why.
When asked about the thought process behind these changes, Adams explained he saw the value of protecting both subscribers and senders through stronger authentication measures and encouragement of best sending practices.
Adoption results are consistent across the board
Adams reported positive initial results from the new requirements, noting a low number of rejections.
Clea Moore, Principal Product Manager at Yahoo, has also observed an increase in senders adhering to the requirements. While she encourages more adoption, she urges senders to view these requirements not as a mere checklist but as a holistic improvement strategy for both subscriber and sender experience. For example, even though the requirement specifies a maximum of 0.3 percent spam complaint rates, senders should aim for a lower figure, closer to 0.1 percent, for better deliverability and a more enjoyable inbox for subscribers.
Dan Givol, Group Project Manager at Google, concurred, noting that the original announcement of bulk sender requirements met minimal resistance from senders. Most are shifting towards fostering stronger, personalized relationships with their subscribers, a goal that necessitates a commitment to best practices.
Post campaign metrics are the key to success
All three mailbox provider representatives preached the importance of metrics. Givol of course pointed to the popular Google Postmaster Tools that can help you track your email performance and reveal places to tweak your campaign approach.
Moore encouraged listeners to sign up for as many feedback loops as possible. This includes third-party deliverability partners for an in-depth look into performance. She also shared the importance of actually receiving and analyzing the feedback from your DMARC record. There’s a reason this requirement is in place; it exists to protect your email program from bad actors and alert you when things are going wrong.
Adams shared that more comprehensive metrics tools will be coming soon from Microsoft, but echoed Moore and Givol’s sentiments for using feedback loops.
Additional guidance from the pros
The audience expressed appreciation for the industry leaders sharing their time and expertise to foster a better inbox. When asked for final nuggets of wisdom to guide senders, here’s what the panelists had to say:
“We get lots of complaints, and it’s about email overload. What we often see is almost a type of bombing, and they get fatigued,” said Adams. He reminded the audience with send volumes at an all-time high, it’s crucial not to overwhelm individuals with messages. He suggested only sending high-value emails and segmenting traffic using different IP addresses for transactional emails, promotional emails, etc., to give subscribers more control over their experience.
Echoing Adams’ sentiment, Moore emphasized the importance of building lasting relationships with subscribers. “I like to think of the relationship with users as a privilege rather than a right, and you have to maintain that privilege,” she said. Fundamentally, senders should only send emails to those who want to receive them.
Givol agreed. “If you are not moving in this direction, it means you are putting this most critical business asset-your customer relationships—at risk,” he explained. He also highlighted the value of understanding mailbox providers’ best practices and requirements, as they will only intensify over time. This isn’t a ‘set it and forget it’ scenario; senders must continually manage and enhance their programs.
At the end of the webinar, all three panelists kindly shared resources to help senders on their compliance journeys.
Sender Guidance
FAQs
Tools for Monitoring
We’re fortunate to have working relationships with mailbox providers and are extremely grateful for their time and expertise during this webinar. Thank you to everyone who joined us live and engaged with questions. If you’d like to watch the full webinar on-demand, you can do so here.