Please note that you cannot use Microsoft Security Defaults or multi-factor authentication (MFA), if you are turning on, please turn off this.
To disable Security Defaults, please check here

To disable MFA, please check here

Also please note that SMTP auth is enabled for the mailbox, check here to see the instruction
Please make sure to enter the correct information in the app:

Email: your office365 email

Password: Your office365 email password

And normally, the rest information you should enter like this:

Updated on: 27 / 07 / 2021