An unknown issue affecting Microsoft's free email service Outlook has left users' email clients borked.
The apparent outage is being widely complained about on sites such as Down Detector and Down Today, where many users have claimed they have been unable to access their accounts through email clients for as long as three days.
While the Hotmail web service is working, those trying to use POP or IMAP to access their email accounts are complaining of authentication issues refusing them entry despite their confidence of using the correct usernames and passwords.
One user on Down Today speculated:
Instead I change the credentials to: "<username>@outlook.com" + <same previously="" valid="" password=""> and I am now successfully able to collect my incoming @hotmail.com email messages.
I wonder if Microsoft has been doing a login credentials clean-up and somehow lost or otherwise invalidated the @hotmail.com login credentials?
The Register has contacted Microsoft regarding this issue but has not received a response as of publication. ®