Office 365 email account – incoming email from it on a wordpress site (even though smtp settings and everything SPF related look good) reports:

“This Sender Failed Our Fraud Detection checks and may not be who they appear to be.  Learn about spoofing at ….”

After several weeks of inconsistent issues around this on incoming email from an Office 365 account, I am pleased to report we have confirmed a resolution:

1st, make sure the obvious culprit is set correctly:  your SPF record where your DNS zone is hosted.  In my case, it WAS correctly setup, and doing tests with MXToolbox on SPF records showed no issues.  However, if you do NOT have your txt record setup to include the domain for your O365 account added to your email server IP, it will not work correctly.

2nd – and this was the issue I logged many hours trying to find – the Office 365 spam filter is interfering and appears to incorrectly block the emails while reporting in the message header that the SPF is the reason it is failing.  Which is CLEARLY not the case.  The solution, as reported online by Robert Peng, is a little complex but solved the issue as we were experiencing it.



Sign into Exchange admin center ( with your Office 365 admin account. In Mail Flow, click + to Create a new rule…, select More options. Set Apply this rule if… – the sender is this person and select the account which sends the emails. Set Do the following… – Modify the message properties – Set the Spam Confidence Level to bypass spam filtering and click Save at last., go to Admin, go to Exchange Admin, go to Mail Flow, go to add a new rule, click More Options, add your sender account(s)


Jeff Shirley

Jeff Shirley

Founder & CEO
Jeff brings over 27 years of experience to the table, along with numerous awards, certifications, and real-world implementations.  His database solutions are currently running in industries including government, mining, agriculture, finance, education, science, research, non-profits, and healthcare businesses around North America and serve thousands of users day to day.  Jeff is a five-time MVP Award recipient for Microsoft Access, acknowledging contributions to community projects, evangelism, and educational outreach on Microsoft technologies.  Today there are less than 50 Access MVP’s worldwide. While Jeff focuses day to day on business management, IoT development, IT integrations and design, database architecture or other typical complex tasks, he also is a co-owner of Blue Heron Gardens, a commercial apiary running over 200 beehives.  Fresh honey is a small perk for many of our clients!

Mitch Redekopp

Mitch works with our clients day to day ensuring web development and IT projects are done to exceed customer expectations.  His background includes formal training in IT, Microsoft and CompTIA certifications, real-world business experience, and a true dedication to ensuring clients receive timely and professional support on their projects with Rivercity Technology Services.  Given the most difficult requests for IT solutions, Mitchell can assist our clients in finding a path to the best options which deliver results for our clients.  Mitchell is an avid soccer player and Manchester City fan, be sure to talk soccer with him when you can.