Case Study: Cutting Through the Noise
Exchange Online Issues Beyond Microsoft
Case Study Overview
When two employees experienced unpredictable email delivery failures, the issue threatened productivity and communication at a global gaming software enterprise. The challenge was compounded by the involvement of third-party software, making the root cause difficult to pinpoint.
US Cloud engineers guided the client through a systematic troubleshooting process, ultimately isolating the true source of the problem and providing clarity, direction, and ongoing support.
Case Stats
Client Industry: Gaming Software/Systems
Technology: Exchange Online
Severity Level: 3
Ticket Number: 122207
What Happened
Two users at the client organization reported that their emails were intermittently failing to send. The issue occurred sporadically—sometimes once or twice a day—while the rest of the company had no problems.
Initially, the users believed the issue stemmed from their Outlook client. Because email is a mission-critical communication tool, even a localized disruption posed risk to operations and user productivity.
Our client’s IT team submitted a ticket to US Cloud to resolve this Exchange Online issue in order to prevent further productivity disruptions from occurring.
Issue Resolution Timeline
- May 14: Client opened a ticket with US Cloud. Users reported sporadic email send failures.
- May– Early June: US Cloud engineers collect data, replicate the issue, and analyze Outlook and Microsoft 365 behavior.
- Mid-June: US Cloud confirms Microsoft services are functioning normally and begins deeper investigation.
- Late June: Using HAR log analysis, engineers identify that outbound emails were being denied by a third-party VPN/security tool (Zscaler).
- July 2: After testing without the third-party service in place, emails began to send successfully and consistently. Ticket closed after client confirms resolution.
(Total duration: 64 days, driven largely by data gathering and client-side testing.)
What US Cloud Did to Resolve the Issue
US Cloud engineers approached the problem methodically:
- Isolated Variables: Our engineers directed users to bypass Outlook desktop and test through web clients to determine whether the issue originated in Microsoft services.
- Ruled Out Microsoft Services: In doing so, engineers confirmed that Microsoft 365 was performing normally, since the issue affected only two individuals out of a large user base.
- Investigated Third-Party Factors: To further explore the issue, US Cloud engineers collected HAR logs from affected users to trace where email delivery was failing. Logs revealed that messages were being routed (and denied) through the third-party security application.
- Validated Findings: Our experts guided the client through temporarily disabling the third-party service, which immediately resolved the delivery issue.
- Provided Direction: Finally, US Cloud engineers equipped the client with evidence that the root cause was external, enabling them to escalate appropriately to their third-party vendor.
Conclusion
While the email delivery issue ultimately stemmed from a third-party application rather than Microsoft services, US Cloud’s engineers ensured the client didn’t get stuck in an endless support loop. By thoroughly ruling out Microsoft as the cause and identifying the true problem, US Cloud provided clarity, actionable next steps, and peace of mind.
This is a different approach than other support services which might simply close the ticket after ruling out Microsoft as the source of the problem.
By going beyond the basics and sticking with the client until the problem is resolved, this case highlights the value of a third-party Microsoft support partner. That is, we help clients navigate complex, multi-technology environments to keep their business moving—even if the source of the problem isn’t a Microsoft product.
