Issue accessing bounce mails with POP

We have configured POP account to retrieve inbound emails in Adobe Campaign Classic v7, this is Windows server installation.
Testing connection at deployment wizard is successful. We know that there are bounce emails in the email account, but for some reason the inMail process is not able to fetch them. We have tried both port 110 and port 995.
According to verbose log the connection looks successful but no messages found.
The bounce email account is a Microsoft account, what could be the issue?

verbose log Loading active POP3 account(s) from the database...
verbose log Connection opened for user '<USER>' on server 'imap.xx.com'
verbose log POP3 Server: '+OK The Microsoft Exchange POP3 service is ready.'
verbose log POP3 Client: 'USER <USER>'
verbose log POP3 Server: '+OK'
verbose log POP3 Client: 'PASS *******'
verbose log POP3 Server: '+OK User successfully logged on.'
verbose log POP3 Client: 'STAT'
verbose log POP3 Server: '+OK 0 0'
verbose log 0 message(s) (0 byte) for user '<USER>'
evrbose log POP3 Client: 'QUIT'
verbose log POP3 Server: '+OK Microsoft Exchange Server 2016 POP3 server signing off.'