Have you configured any mail templates?
if so, Template From mail address and your configuration from address and username should be same
From the settings visible in your screenshot, it is correct https://support.microsoft.com/en-us/office/pop-imap-and-smtp-settings-8361e398-8af4-4e97-b147-6c6c4ac95353
I bet a firewall rule is preventing you to connect from the Mendix server to the SMTP Server. If you run the app locally, it could be the corporate firewall. I would suggest “just to publish” it like this and see if from the Mendix Cloud you do get access.
Go Make IT.