In this post, Microsoft MVP Alan Byrne explains how to configure the two most effective technologies that will ensure your outgoing email is successfully delivered. These technologies are known as Sender Policy Framework (SPF) and DomainKeys Identified Mail (DKIM), and they protect your outgoing emails from being marked as spam while also flagging and blocking any incoming messages from unauthorized servers spoofing your domain.
A recent increase in email spoofing false positives causing legitimate email to go to Outlook junk folders can be explained by a change in Office 365 Advanced Threat Protection.
A curious case of legitimate Azure Active Directory Identity Protection weekly digest emails being quarantined by Exchange Online Protection when international spam filtering is enabled.
Are Sender Policy Framework (SPF) records in DNS necessary for domains these days?
Email messages may be found in the Junk Email folder of Outlook with a message that fraud detection checks failed, warning that the message may be spoofed.