Yes, this is super annoying.
I keep getting SMTP errors like: 334 VXNlcm5hbWU6 UGFzc3dvcmQ6 Authentication unsuccessful [BL1PR13CA0304.namprd13.prod.outlook.com 2026-01-22T20:59:23.476Z 08DE59C2EA6C3D25]
and: '550 (x.x) [x.x.x.x]:xxxx is currently not permitted to relay through this server. Perhaps you have not logged into the pop/imap server in the last 30 minutes or do not have SMTP Authentication turned on in your email client.'
See also:
https://news.ycombinator.com/item?id=46724962
https://news.ycombinator.com/item?id=46724544
https://www.reddit.com/r/msp/comments/1qk45c0/microsoft_serv...
https://www.reddit.com/r/sysadmin/comments/1qk3tg7/microsoft...
https://www.reddit.com/r/sysadmin/comments/1qk518l/email_ser...
Exchange online is down down. All the MX records are returning SERVFAIL, so something has gone quite badly on MS's side. It could be load shedding, or their authoritative DNS has blown up.
IMAP seems to also be having some sort of problem... Thunderbird has been stuck at "Looking up outlook.office365.com..." for a while.
It's spreading - just hit us about 20 minutes ago, and it's creeping outward. DNS went kablooie - someone's having a horrible day.
How is this not the top of the front page?
Are we just immune to these headlines now because we don’t expect anything different from Microslop? Just an assumption that they’ll have a catastrophic failure once a quarter or more.
If you take a look, you can see comparable bumps during events like these across a wide array of sites and services, indicating a shared point of failure. Given the extreme weather, it's a tossup as to whether this was a fiber cut or a config screwup - could be bad BGP or routing, or possibly even an intentional cutover in preparation for possible outages, swapping primary and backup.
Lots of possible root causes, and it's at a level that consumers probably won't get a clear answer right away.