micejib
2878 posts
Jan 31, 2026
5:16 AM
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Email office 365 spf record security and deliverability are critical for any organization using Microsoft 365 (formerly Office 365). One of the most important — and often misunderstood — components of email authentication is the Office 365 SPF record. If your SPF record is missing, incorrect, or misconfigured, your emails may land in spam folders or be rejected entirely.
In this article, we’ll explore what an Office 365 SPF record is, why it matters, how it works, how to configure it correctly, and common mistakes to avoid.
What Is an SPF Record?
SPF stands for Sender Policy Framework. It is a type of DNS (Domain Name System) record that tells receiving mail servers which servers are authorized to send emails on behalf of your domain.
When an email is sent, the receiving server checks the SPF record of the sender’s domain to verify whether the sending server is allowed. If it’s not listed, the message may fail authentication and be marked as spam or rejected.
What Is an Office 365 SPF Record?
An Office 365 SPF record is a specific SPF configuration that authorizes Microsoft 365 mail servers to send email on behalf of your domain.
If your domain sends mail using Outlook, Exchange Online, or other Microsoft 365 services, you must include Microsoft’s SPF mechanism in your DNS records. Without it, email sent from Office 365 may fail SPF checks.
Why the Office 365 SPF Record Is Important
A properly configured Office 365 SPF record provides several benefits:
1. Improved Email Deliverability
Emails authenticated with SPF are far less likely to be flagged as spam by Gmail, Yahoo, Outlook, and other providers.
2. Protection Against Spoofing
SPF helps prevent attackers from sending fake emails that appear to come from your domain.
3. Compliance With Modern Email Standards
Many email providers now require SPF (along with DKIM and DMARC) for reliable delivery.
4. Better Domain Reputation
Domains with correct SPF records maintain a stronger sending reputation over time.
How SPF Works With Office 365
Here’s a simplified version of how SPF works in Microsoft 365:
An email is sent from an Office 365 mail server.
The recipient’s mail server looks up the sender’s domain SPF record in DNS.
It checks whether the sending IP or hostname is authorized.
If authorized ? SPF Pass
If not authorized ? SPF Fail, SoftFail, or Neutral
The result affects whether the email is delivered, quarantined, or rejected.
The Default Office 365 SPF Record
Microsoft recommends the following SPF record for domains that only send email using Office 365:
v=spf1 include:spf.protection.outlook.com -all
Explanation of Each Part
v=spf1
Declares the SPF version.
include:spf.protection.outlook.com
Authorizes Microsoft 365 mail servers.
-all
Hard fail for all other sending servers (recommended for security).
Office 365 SPF Record With Third-Party Senders
Many organizations use additional services like:
Mailchimp
SendGrid
Salesforce
Zendesk
Marketing automation platforms
Website contact forms
In this case, your Office 365 SPF record must include all legitimate senders.
Example SPF Record With Office 365 and a Third-Party Service
v=spf1 include:spf.protection.outlook.com include:sendgrid.net -all
?? Important: You can only have one SPF record per domain. Multiple SPF records will break authentication.
How to Add or Update an Office 365 SPF Record
Step 1: Identify Your DNS Hosting Provider
This may be GoDaddy, Cloudflare, Namecheap, Google Domains, or your hosting company.
Step 2: Locate the SPF Record
SPF records are stored as TXT records in DNS.
Step 3: Create or Edit the TXT Record
Host / Name: @ or your domain name
Type: TXT
Value: Your SPF record (example below)
v=spf1 include:spf.protection.outlook.com -all
Step 4: Save and Wait for DNS Propagation
Changes can take anywhere from a few minutes to 48 hours.
Office 365 SPF Record Limitations and Best Practices
DNS Lookup Limit (10 Lookups)
SPF has a hard limit of 10 DNS lookups. Exceeding this limit causes SPF to fail.
Best practices:
Avoid unnecessary include statements
Remove unused services
Use SPF flattening if needed
SoftFail vs HardFail in Office 365 SPF Records
SoftFail (~all)
v=spf1 include:spf.protection.outlook.com ~all
Less strict
Emails may still be delivered but marked suspicious
Useful during testing
HardFail (-all)
v=spf1 include:spf.protection.outlook.com -all
Strong security
Unauthorized emails are rejected
Recommended for production environments
Common Office 365 SPF Record Mistakes
Creating multiple SPF records
Forgetting to include third-party senders
Exceeding the 10 DNS lookup limit
Using +all (allows anyone to send mail)
Not updating SPF after adding new services
SPF vs DKIM vs DMARC in Office 365
While SPF is essential, it works best alongside DKIM and DMARC:
SPF – Verifies sending servers
DKIM – Verifies message integrity
DMARC – Tells servers how to handle failures
Microsoft strongly recommends using all three for maximum security and deliverability.
How to Test Your Office 365 SPF Record
You can test your SPF configuration using:
Microsoft Message Header Analyzer
Online SPF validation tools
Email authentication testing services
Always test after making changes to avoid delivery issues.
Final Thoughts on Office 365 SPF Records
A correctly configured Office 365 SPF record is a foundational requirement for secure and reliable email delivery. Whether your organization sends email exclusively through Microsoft 365 or uses multiple third-party services, maintaining an accurate SPF record helps protect your domain, improve inbox placement, and build trust with recipients.
If you’re setting up Microsoft 365 for the first time or troubleshooting email delivery issues, reviewing your SPF record should always be one of the first steps.
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