Service degradation on Microsoft 365 (Business or Enterprise)

status.cloud.microsoft

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.'