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Improving Inbox Placement for Outlook and Microsoft 365 Users

Updated over a month ago

Having trouble getting your cold emails into Outlook inboxes? You’re not alone. Microsoft 365 is one of the strictest platforms when it comes to email deliverability, but with the right setup, you can consistently land in the inbox.

This guide walks you through the proven process for optimizing your cold email setup, especially when your campaigns target Outlook or Microsoft 365 users.

Let’s get started 🚀

1. Set Up SPF, DKIM, and DMARC

Microsoft requires email authentication to validate your domain. Without these DNS records, your emails are more likely to hit spam, even if the content is good.
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  • SPF: Add this TXT record to your DNS:
    ​ v=spf1 include:spf.protection.outlook.com -all

  • DKIM: Enable this in the Microsoft 365 Admin Center. Microsoft will generate the CNAME records for you.
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  • DMARC: Use a TXT record like:
    ​ v=DMARC1; p=none; rua=mailto:[email protected]

Try EasyDMARC’s free record generators or follow Microsoft’s DKIM setup instructions in the admin panel.

2. Use a Secondary Domain + Microsoft Mailbox

Don’t send cold emails from your main business domain.

Instead:

  • Register a similar secondary domain (e.g., if your main domain is b2brocket.com, try b2brockethq.com)
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  • Use GoDaddy to register and set up a Microsoft 365 mailbox ($2/month Essentials plan)

For more information on Adding a Microsoft account to B2B Rocket so you can send emails directly from your Outlook.

Why GoDaddy + Microsoft?

  • Microsoft inboxes prefer emails from Microsoft servers
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  • GoDaddy preconfigures SPF records and makes mailbox setup easier
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  • Avoids rDNS issues tied to other registrars

3. Warm Up Mailboxes with b2brocket

New or inactive mailboxes need time to build a good reputation before sending bulk emails. For more information, refer to the Warm-Up Settings document.

  • Start with 2–5 warmup emails/day
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  • Ramp up gradually to 50/day
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  • Turn on reply simulation and read emulation

Use a custom tracking domain (add a CNAME in your DNS for this)

4. Keep Your Lists Clean

Microsoft filters aggressively based on bounce rates. Bad emails = bad results. Before uploading to B2B Rocket:

  • Clean your list with MillionVerifier
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  • Segment risky emails into a separate campaign
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  • Avoid scraped or low-quality lists

Tip: B2B Rocket’s Lead Finder provides fresh, filterable data. Always export only what matches your ideal persona.

5. Write Emails That Microsoft Will Trust

Even with a perfect setup, poor email content can land you in spam. Here’s what works:

  • Short subject lines with curiosity (e.g., “Your sales team?” or “Quick idea?”)
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  • 5–6 sentence emails, no links or images
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  • Use personalization via AI (first name, company name, pain point)
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  • Always include an unsubscribe option and mailing address

Avoid:

  • Spammy language (“free,” “discount,” “100% guarantee”)
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  • Dollar signs, percentages, emojis
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  • Overused cold email templates

For more information, refer to the Cold Email Copy best practices document.

6. Monitor Deliverability and Stay Consistent

Tracking your email health over time helps avoid issues. What to monitor:

  • Open Rate: Aim for 30% +
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  • Reply Rate: Target 10%+
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  • Bounce Rate: Stay under 3%
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  • Spam/Complaint Rate: Keep below 0.1%

Use tools like:

Tip: And don’t send too many emails too quickly, Microsoft flags sudden spikes in volume. For more.

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