If your email went down today, you're not alone - millions of Microsoft Exchange users across the world were affected by an outage that stopped people logging in to their email accounts.

Microsoft Office 365, the cloud service that powers Outlook as well as newer versions of Word, Excel and Powerpoint, suffered an outage across Europe and the Asia-Pacific region for several hours.

Service was resumed just before 1pm UK time, with the company stating on Twitter that an "authentication issue" had now been "resolved" - although some users were still complaining that they could not log in.

Earlier, users reporting the problem were sent a standard Twitter response that said: "We're investigating reports of our dear customers having issues with logging in to Microsoft Account/Office 365. Our Network Operations Center Engineers are currently working to resolve this. More details will be provided shortly."

Perhaps not coincidentally, the outage came mere hours after Microsoft announced it was rolling out changes to Office 365 that would "help further protect individuals and families from online threats."

While the problem remained unresolved, users across the UK, Europe and Asia were without access to email for several hours.

But at least some people could see the funny side: