alt Hacker NewsSure, outlook.com is down, which is bad for everyone that chose to host their email there, I guess, but as an interesting side-effect, everyone with an on-premise Exchange server and "new Outlook" clients is affected as well.
Because, well, once upon a time there was Exchange Server and MAPI (the "Messaging API"), and that actually worked pretty well, and pretty much everyone started using it (or one of its EWS/ActiveSync offshoots), but then the Internet happened and ruined everything, but we got MAPI-over-HTTPS eventually, which by that time had grown so many warts that nobody at Microsoft really understood it anymore, so that got deprecated, even though, well, everyone and everything still uses it.
The new hotness was Azure-slash-Office-365, and that's where the "new Outlook" web interface lived and (sort-of) continues to live, and the on-prem customers got stuck with the "Exchange Subscription Edition", which was basically Exchange 2019 plus security hotfixes at extortionate rates, but with none of the new functionality.
And, since MAPI continued to be really, really hard even in the age of Copilot, access from the new hotness to the deprecated on-prem servers was implemented via IMAP (LOL), but force-proxied via the outlook.com cloud/clownshow.
Which is why, right now, many Microsoft customers that thought they were self-hosting their email are entirely down. Lessons might be learned here, but I sort-of doubt it...
Replies
Do e-mail messages that self-hosted Exchange receives always get proxied through the outlook.com cloud?
Thanks for this LMAO. It made my day off worth taking. Now I don't feel the need to log in and check who-knows-what mail.
Exchange has been a circus for years. I think that's why everyone went O365 in the first place. Managing to have a paid up configuration where you go down when a cloud provider goes down but you're hosting it locally is absolutely stupid and I am laughing my ass off here.
Also laughing at our ops guys who are now absolutely helpless and have people phoning them. I warned about this on our risk call and it was seen as low probability low risk. I hope it's down for a few hours :)
I don't think many orgs are using "new Outlook" to connect to on-prem Exchange because you miss a lot if you're only doing it via IMAP and "new" still doesn't support on-prem Exchange any other way. So all my clients are using classic Outlook with their on-prem Exchange servers (and really if they have EXO too because new Outlook isn't very good).