SPF Record Setup for Office 365
Office 365 users may find that Microsoft has restricted the ability to edit the SPF record that is automatically provided to you.
We recommend that Office 365 users switch DNS hosting over to another DNS provider, such as https://www.cloudflare.com/dns
You would need to copy over your existing DNS settings from your current Microsoft-hosted DNS.
After making the switch you will be able to modify the SPF record and you'll likely also see faster DNS performance.
We have instructions for editing an SPF record at CloudFlare.