12 / September / 2025

New rules for bulk email: what are Google, Yahoo and Microsoft bringing?

From 2024, the world of emailing is changing. Google, Yahoo, and now Microsoft are introducing stricter rules for bulk senders. If you're sending newsletters, sales offers or transactional emails in high volume, you definitely shouldn't miss this.

1. Authentication is the new standard

Since February 2024, Google and Yahoo began requiring all bulk senders to have SPF, DKIM and DMARC set up correctly. Microsoft joined in with its own rules in April 2025.

What does this mean in practice?

SPF tells which servers can send emails on your domain's behalf.
DKIM adds a digital signature to emails to verify their authenticity.
DMARC determines what should happen if a message fails authentication - and helps guard your reputation.

If you do not have these records set up, your emails may be rejected or end up in spam. And this has been the case with Microsoft since May 2025.

2. Spam rate below 0.10 % - or you're in trouble

Google now requires the rate of marking your emails as spam to be less than 0.10 %.

If you go over 0.30 % for a long time, count on warnings or outright blocks.

What can you do?

Get rid of inactive contacts.
Segment and send relevant content to the right audience.
Use a preference center where users can set the frequency and type of communication themselves.

3. Easy unsubscribe? A must.

Marketing emails must allow one-click unsubscribe. Google now actively requires this, and any attempt to circumvent it can damage your domain reputation.

In addition, in July 2025, Google has introduced a "Manage Subscriptions" feature in Gmail where users are able to view and manage their newsletters in bulk. This increases the importance of transparent and ethical communication.

4. Microsoft: Tough stance on bulk senders

As of May 5, 2025, Microsoft (Outlook.com, Hotmail, Live):

Blocks emails from unverified domains
Requires SPF, DKIM and at least DMARC with p=none policy
Imposes a limit of 2,000 messages per day to external addresses (for Exchange Online from 2025)

If you use Exchange Online and send a lot of emails, you should switch to a different infrastructure (e.g. Azure Communication Services).

5. Email is no longer enough: Multichannel wins

These changes point to one clear conclusion: e-mailing cannot work on its own.

Integrate push notifications, SMS, social media
Tailor communication to each customer across channels
Use ABM campaigns that combine personalized emails with display advertising and social media

As Natalie Jackson of CBIZ says:

"E-mail can no longer live in isolation. Without connectivity to other channels, we are losing vital insight into customer behavior and into the impact of our activities."

What to do now (even if you already have "everything")

Check and update SPF, DKIM, DMARC
Track spam rates (e.g. in Google Postmaster Tools)
Establish a preference center
Ensure that all teams (including sales) send emails through the correct domain
Get ready for Gmail's "Manage Subscriptions" feature
Think about your overall communication - don't let email be an isolated channel

Conclusion

These are not just cosmetic changes. This is the new reality of emailing in 2025 and beyond. Those who adapt will have an advantage - not just in deliverability, but in brand perception and customer trust.