Using Outlook for Android in business environments for email and scheduling
I don't think it's possible in Lite Outlook right now... Seems like there's just the option to receive notifications for all emails.
I've got the same issue on my Samsung S8 as well... The workaround I found was to log in Samsung Email to my Outlook email account, because it has a similar system called VIPs. I can receive email notifications from my Outlook email address for the contacts I want, and then view the emails in the outlook app... It doesn't matter to me that the notifications come from a different app. But it's only a workaround - I hope this issue gets fixed soon.