I am aware that you guys received an email from a trusted source and have been added to your safe list, but keep getting a warning message:
Be careful! This sender failed our fraud detection checks
To resolve this issue, the sender’s domain administrator should add the SPF record in the domain registrar. You may contact the sender's administrator to verify this information.
If your custom domain is registered through Windows Live Admin Center, please add the SPF record value to your registrar.
If issue persist, please create a new post and provide us with the following:
•Sender of the email
•Sample of the email or message source
NOTE: I have locked this thread now.
We are already aware of this issue and we have already forward this to our Product team. In the meantime, we advice you to mark any emails as Phishing scams if you are not sure about it. You can also review email headers if in doubt for messages that seem suspicious.