Dec 18 2022 11:42 PM - edited Dec 18 2022 11:44 PM
Hi,
We had a problem with SMTP authentication for our tenant M365.
Here is the brief story....
It can authenticate formerly but can't authenticate suddenly starting from 5th December 2022. After we have digested some documents from Microsoft, SMTP protocol still can authenticate even after deprecation of Basic Authentication. Ref: Basic Authentication Deprecation in Exchange Online – September 2022 Update - Microsoft Community Hu...
We have turned on Multifactor authentication in our tenant but already turned off the security default in Azure AD since it can impact to SMTP protocol to send out the message if ON.
Then we have opened the ticket to Microsoft and the support agent provided us to try the following method....
1) enable SMTP auth in active users > mail apps > check SMTP authentication
2) enable SMTP auth using PowerShell commands in exchange online
After running some command as instruct, we got the following result
Get-TransportConfig | Format-List SmtpClientAuthenticationDisabled
SmtpClientAuthenticationDisabled : False
The above result means SMTP is enabled. However, we still can't authenticate
We have tested with outlook 2016 - IMAP configuration.
incoming : outlook.office365.com/ 993/SSL
outgoing : smtp.office365.com/587/TLS
Note: we can understand that incoming mail won't work since we have disable Basic Authentication and incoming should got error but outgoing with SMTP should work.
As I mentioned earlier, it works fine before 5th of Dec 2022.
My question is that, is there any way to fix this issue since it still can't handle be microsoft agent with wired solution which won't work
Why Microsoft didn't care including the support agent can't handle long time.
Thank you
Dec 19 2022 08:39 AM
Dec 19 2022 08:19 PM