In a touching Monty Python tribute today, Microsoft's Office 365 makes everything spam

Punters less amused by inbox-clearing glitch

A gremlin within the spam filters in Microsoft's Office 365 today caused the cloud-based service to toss all incoming emails into the junk folder.

On Wednesday afternoon, US West Coast time, IT administrators and users publicly complained of similar issues: their Office 365 email systems were marking legitimate messages as spam and filtering them out of sight along with actual junk mail.

Be advised there are issues with #Office365 spam/phishing filtering possibly junking legitimate items, including existing items! #EX135575 pic.twitter.com/oSvCOuI0op

— Michel de Rooij (@mderooij) April 25, 2018

Office 365 service partners are also noticed the problem...

@Office365 We are a Microsoft referral partner and several of our clients (the number keeps climbing) are reporting that incoming emails are being flagged as Spam by Microsoft and moved to their Junk email folders

— Sondra Lorino (@SondraLorino) April 25, 2018

We started receiving these on many trusted emails today. Anyone else seeing these? Bad Office Malware Update? @mikael_nystrom @jarwidmark @SwiftOnSecurity https://t.co/rYG8yLhXBc

— Greg Gallaway (@VoIP_Guru) April 25, 2018

By 5pm Pacific Time (midnight UTC), Microsoft said it had reversed the cockup, and was busy cleaning up the mess.

"We've addressed the underlying issue and affected emails are being refiled into the right folder,” a spokesperson told The Register.

In the meantime, enjoy this rare chance to use "it must have been tossed to the spam folder by accident" as an actual viable excuse for ignoring a memo.

It has been a bad week for webmail services. Over on Gmail, users have been complaining for days that spammers are flooding their inboxes with spoofed-header emails that show up as being from the users themselves, including saving copies of the spam to the users' outgoing mail folders. ®