Microsoft Email Updates - What You Need to Know
- Bryn Tyler
- May 5
- 2 min read
Updated: May 8

Big Email Changes Coming from Microsoft - But HMA Clients Are Already Ahead of the Curve
What hotel marketers need to know about the May 5, 2025 update
Starting May 5, 2025, Microsoft is rolling out new email authentication requirements that could impact how your emails land (or don’t) in inboxes. If you're sending to addresses like @outlook.com, @hotmail.com, @live.com, or even business accounts hosted through Office365, this update affects you.
So, what’s changing? Microsoft is tightening the rules to make inboxes more secure. They’ll begin enforcing stricter standards for email authentication - meaning if your messages don’t pass SPF, DKIM, and DMARC checks, they may be blocked or flagged as spam.
It’s technical, yes - but it’s all about proving your emails are coming from a trusted source.
A heads-up on no-reply addresses Another important part of Microsoft’s update is a new requirement around the From Address and Reply-To Address. Starting May 5, either the From address or the Reply-To address must be a real, working mailbox - not a “noreply@” or invalid inbox.
At HMA, we think this is just the beginning. While Microsoft currently says either field must be valid, we believe this is a prelude to requiring both to be functional in the near future. That’s why we’ve already shifted all of our campaigns to use real, monitored inboxes that allow for proper guest communication and bounce handling - and we recommend the same for everyone else.
What this means for your hotel’s marketing
Without the right authentication setup, even your best-designed campaigns - welcome emails, pre-arrival upsells, booking confirmations - could get tossed into spam. And if you’re still using a noreply address? There’s a good chance Microsoft will stop accepting it altogether very soon.
HMA clients - you’re good to go
If you’re partnered with HMA, you’re already covered. We’ve had proper authentication protocols like SPF, DKIM, and DMARC in place for years - and we never use no-reply addresses in our campaigns. It’s all part of making sure your emails land where they should: right in your guests’ inboxes.
For everyone else…
If you're managing email on your own or with another provider, now’s the time to:
Verify your SPF, DKIM, and DMARC records
Make sure you’re sending from a real domain and real mailbox
Avoid using noreply@ addresses for either the From or Reply-To fields
Reach out to your ESP or IT team for support before May 5 rolls around
___ Need a quick deliverability audit or help getting your domain squared away? Just reach out - we’re here to help hotels stay ahead of the curve. Reach out to your HMA account Rep or send an email to hello@wearehma.com to find out more!
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