To authorize Microsoft Office 365 to send emails on your behalf you will have to manually add it to your SPF record. The SPF record mechanism used for Office 365 is:
If Office 365 is your only sender your SPF record will look like the below example:
v=spf1 include:spf.protection.outlook.com -all
NOTE: The only scenario for which you should not have to do anything is when you are fully hosted on Office 365 in which case everything will be set up for you by default.
If you have other senders authorized in your SPF record, do not create a new SPF TXT record, simply add “include:spf.protection.outlook.com” to your existing SPF record.
You can verify if you’ve correctly authorized office365 in your SPF record via our SPF record checker.