Security: O365 – did you remember to disable legacy authentication before October 13, 2020?
If you have kept up to date with the many announcements around 365 – spesifically Exchange Online, from Microsoft, you may remember that they announced that end of support for basic authentication were coming to various parts of Exchange Online in 365.
Subscribers of O/M365 should move to using modern authentication, as this is more secure and gives alot of other benefits.
The said date for this change was set to October 13 2020,