I was able to get pop3 in vro to work with O365 by first importing the O365 cert.
Go to Library>Configuration>SSL Trust Manager
Run Import a certificate from URL using the url: Outlook.office365.com
You need to import the cert from smtp.office365.com using the same “Import a certificate from URL” wf before you can use the smtp functionality as well.
Be sure that yes to SSL is selected when you run 'Retrieve messages (via MailClient). Port should be 995.