Microsoft has been having issues with Outlook.com for the past week, but the company says it's found a fix, which it's currently deploying.
A mystery bug has prevented Outlook.com users from accessing or syncing their accounts from apps and smartphones since last Thursday. Six days on since logging the issue, Microsoft today said it's rolling out a fix that should soon resolve the connection problems for users.
"We've completed the fix and are deploying it throughout the affected environment. While the fix is being deployed, some users may begin to access and synchronize their Outlook.com accounts while using applications or mobile devices," Microsoft says on an Office 365 status page.
For those who still can't sync their accounts with mobile devices, the company is recommending they log in to Outlook using a web browser, which is exactly what many users have been forced to do for the past week.
It's not clear from Microsoft's posts what the root cause of the issue is, nor why it's taken so long to close the report. However, Microsoft noted on Wednesday that it was deploying the fix to "affected infrastructure".
Down Detector's heat map suggests most issues with Outlook are being reported by users in Europe.
The site's comment section has also piled up with nearly 10,000 reports that match Microsoft's description. Many users report being been unable to access Outlook from apps on iOS and Android for the past two to three days, but others report issues syncing since last Thursday.
Some are also reporting Hotmail has been unavailable for several days, while others say the disruption is also affecting the Outlook client on desktop.
ZDNet has asked Microsoft to shed light on the cause of the syncing issues and will update the story if it receives a response.
Outlook has been undergoing a major migration since 2015 as part of Microsoft's effort to align Outllook.com with its Outlook client.
However, as of April 2016, it had migrated less than half of its 400 million Outlook.com accounts. It was also moving Outlook.com to Office 365's more modern infrastructure, and rolling different groups across to the new system in separate batches.
It's unclear whether the migration has been completed yet. Readers from Thurrot.com in August reported receiving a notification from Microsoft that it was currently upgrading Outlook.com and that it would complete its Outlook migration in the first half of 2017.