For outbound email sending the account which will be used must have
SMTP Auth (Basic authentication) enabled.
Information on how to enable basic authentication can be found in the following Microsoft article:
How to set up a multifunction device or application to send email using Microsoft 365 or Office 365: Option 1If the Office 365 email account that will be used for SMTP outbound sending has MFA enabled, it is recommended to use an App password to avoid issues when using it in the SMTP configuration.
The SMA cannot complete an MFA check, it will cause authentications issues when it tries to send outbound emails using SMTP.
The following Microsoft article supplies guidance on enabling App Password and where to create them.
Allow users to create app passwordsOnce enabled, you can add the sign-in method “App Password” for the account in question in the following link:
My Sign-Ins - Security infoNOTE: This password will not work for OAUTH authentication, which will require the account password to be used and MFA authentication to be completed.
Once you have your app password you can test it in your Service Desk queue (or in Network Settings) and if everything is correctly configured you should get a successful email test in the inbox for the email you entered for the test.
For OAUTH configuration please review KB article 4318726
How to configure OAuth on the Kace SMA Service Desk for incoming emails using Office365 (4318726)