On a problem report issued on Microsoft's site, the company has apologised profusely to customers for outages that may have affected them this week on Outlook.com or Exchange ActiveSync.
According to the post, "the incident was a result of a failure in a caching service that interfaces with devices using Exchange ActiveSync, including most smartphones."
Many users would have faced an error and an inability to connect to the service.
Although the services were restored quickly, The Next Web notes that some users faced issues with the service as long as three days.
The statement from Microsoft explains that the initial failure caused an influx of traffic which Microsoft's services didn't handle correctly resulting in the unstable Outlook.com services.
Due to this, users were unable to connect to their email or share their SkyDrive files via. email.
In order to resolve the issue, Microsoft "temporarily blocked access via Exchange ActiveSynce."
This resulted in being able to restore access to Microsoft's other services that had suffered from the flood of traffic.
Microsoft admits it has learnt from the incident and has made two changes to the networks.
"One that involved increasing network bandwidth in the affected part of the system, and one that involved changing the way error handling is done for devices using Exchange ActiveSync," the problem report states.