Will basic auth continue to work with SmtpClient in C# applicaiton to send email to Exchange server after 31st Dec 22

Question

We are using SmtpClient in C# console application using basic authentication (uname and password) to connect to exchange server smtp.office365.com for sending email.
Microsoft is disabling basic auth for exchange server on 31st Dec 22 but read at some places that Microsoft will disable for all except for SMTP Auth.

Queries -

1) So the question is after 31st Dec 22 will our C# console application still be able to send email to the exchange server using basic authentication ?

2) If no, then what is the alternative ?

3) If yes , then for how many more days (ideally its recommended to move away from basic which we will try later but is there any other deadline like 2023 to disable basic auth for SmtpClient also ?

Answer 1

you have had 3 years notice. in oct, a one time extension to 12/31/2022 was allowed.

1) no, it will not work
2) replace the SmtpClient (which is depreciated) with a different library before the end of the year.
3) sometime the week after 12/31/2022 is the last day SmtpClient can call online exchange

https://techcommunity.microsoft.com/t5/exchange-team-blog/basic-authentication-deprecation-in-exchange-online-september/ba-p/3609437