Why Your Legitimate Emails Might Suddenly Be Going to Junk
If you’ve noticed clients not receiving quotes, newsletters, or invoices lately — it may not be a coincidence. In early 2025, Microsoft introduced new requirements for bulk email senders using Outlook and Microsoft 365.
This means even if your business is sending legitimate messages, those emails could be blocked or marked as spam if your setup doesn’t meet the new standards.
Let’s unpack what’s changed, why it matters, and how to protect your business communications.
What Are the New Outlook Email Rules?
Microsoft now requires bulk senders (anyone sending more than 5,000 emails per day to Microsoft addresses) to:
✅ Authenticate their email domains using SPF, DKIM and DMARC
✅ Include a one-click unsubscribe link in all bulk messages
✅ Keep spam complaint rates below 0.3%
And even if you’re not sending 5,000+ emails per day, your emails can still be impacted if Microsoft flags suspicious sender behaviour.
⚠️ Emails may be silently blocked — meaning they won’t bounce back or show as failed, they just won’t be delivered.
Why This Matters for Aussie SMBs
Most small and mid-sized businesses use tools like Mailchimp, HubSpot, or ActiveCampaign to communicate with customers. These tools rely on your email domain settings being correct.
If your domain isn’t authenticated, or if you’re sending from a shared domain without protections in place, your business emails might:
- Land in spam or junk folders
- Be blocked altogether
- Look suspicious to clients — damaging your reputation and trust
How to Check if You’re Compliant
1. ✅ Set Up Email Authentication
Your domain needs to be secured with:
- SPF – Specifies who can send emails on your behalf
- DKIM – Ensures messages haven’t been tampered with
- DMARC – Tells receiving servers what to do if an email fails SPF or DKIM
🛡️ At Calibre IT, we manage this automatically for our clients using Sendmarc, a powerful email security platform designed for businesses of all sizes.
2. 🔄 Review Your Bulk Email Tools
Are they sending “on behalf of” your domain or using shared delivery systems? If so, deliverability could suffer.
3. 📉 Monitor Spam Complaint Rates
A single campaign that gets marked as spam too often can sink your domain reputation.
4. 📬 Add a Visible Unsubscribe Link
Required by Microsoft and Google — and just good practice for user experience.
Real-Life Example: A Brisbane Logistics Firm
One of our clients — a mid-sized logistics company — found that their invoices and job confirmations were getting ignored. We ran a domain health check and found missing DMARC records.
After configuring authentication via Sendmarc, their emails started landing properly again — restoring trust, cash flow, and visibility.
The Bigger Picture: Trust, Security & Visibility
These changes are about more than just jumping through hoops. They’re designed to:
- Prevent spoofing and impersonation
- Improve global email security
- Ensure legitimate businesses like yours don’t get caught in the crossfire
What You Can Do Today
Here’s your action plan:
🔍 Use a free tool like MXToolbox or Sendmarc to check your domain
🛠 Ask your IT provider to confirm SPF, DKIM, and DMARC setup
📈 Monitor email performance for bounces and complaints
📨 Review unsubscribe functionality in all bulk emails
Not Sure If You’re Compliant?
We offer a free email domain health check using Sendmarc — no jargon, no sales pitch. Just clear advice on whether your setup meets Microsoft’s new standards.
👉 Book your free email check now
Written by the team at Calibre IT, helping Aussie businesses stay secure, compliant, and connected.
