Microsoft is investigating Change On-line mail supply points inflicting “Server busy” errors and delays when receiving emails from outdoors organizations.
Based on person reviews on-line, the Change On-line issues began this morning, affecting Microsoft 365 clients worldwide, throughout the Americas, Europe, and Asia.
Microsoft confirmed the continuing points this morning, at 6 AM GMT+2, saying that “some customers might encounter delays receiving exterior electronic mail messages in Change On-line. Affected customers might even see a ‘451 4.7.500 Server busy’ error message.”
“We’re analyzing pattern throttling IPs from easy messages to substantiate whether or not the problem with the portion of SOL infrastructure is inflicting affect, earlier than we start formulating a remediation plan,” the corporate added.
“Impression is restricted to some customers who’re served by way of the affected infrastructure.”
Extra data on these ongoing Change On-line points is obtainable below EX680695 within the Microsoft 365 admin middle.
Linked to IP-address anti-spam guidelines
In a subsequent replace, Redmond mentioned the reason for the problems may very well be linked to the misguided enforcement of IP handle anti-spam guidelines for affected clients.
“We have recognized {that a} latest service replace, utilized to a bit of infrastructure answerable for implementing IP handle anti-spam guidelines, comprises a change which is inadvertently inflicting affect,” Microsoft mentioned.
This confirms person reviews saying that, in some instances, they’re seeing hundreds of emails added to the outbound queue due to Change On-line’s spam filter.
Microsoft has but to substantiate the areas affected by this Change On-line outage and if it additionally impacts Change On-line outgoing mail supply.
At the moment’s incident follows a number of Change On-line outages for the reason that begin of the yr, blocking clients worldwide from accessing their mailboxes and sending or receiving emails.
It is a growing story …
