Microsoft is investigating an ongoing Trade On-line outage stopping clients from sending emails and triggering 503 errors on affected techniques.

Impacted customers report having points with emails despatched from Microsoft 365 environments being returned with “503 5.5.1 Dangerous sequence of instructions” errors.

“We’re investigating a difficulty the place some customers could also be unable to ship Trade On-line e mail messages because of a current change to the free/busy infrastructure,” Redmond tweeted.

“We’re figuring out a plan to resolve the influence. Additional particulars will be discovered beneath EX649175 within the admin heart.”

As the corporate confirmed within the EX649175 ticket within the Microsoft 365 admin heart, some customers could expertise points when sending Trade On-line emails and see “Dangerous sequence of instructions” errors.

“We’re reviewing service monitoring telemetry to isolate the basis trigger and develop a remediation plan,” Microsoft added.

“Affect is restricted to some customers who’re served via the affected infrastructure.”

The corporate has but to disclose which Microsoft 365 areas this Trade On-line outage impacts.

Nevertheless, primarily based on buyer stories, the influence has unfold to customers in america, Europe, India, and the UK.

Two weeks in the past, Redmond additionally addressed an Outlook.com concern stopping customers from looking out their emails and triggering 401 exception errors saying, “Sorry, one thing went flawed. Please strive once more later.”

In June, Redmond addressed one other outage stopping American clients from accessing their Trade On-line mailboxes by way of Outlook on the net.

It is a growing story …