Mail app on iMac not showing all messages appearing on iPad

mail not showing all messages MacOS on older (2015 vintage) iMac running Monterrey 12.7.6. I sent a password request to a third party, the reply messages appeared on the Mail app on my iPad, but never appeared on my iMac. My mail server uses Outlook, I do not know details. I've tried to find if the sender from the third party mentioned is somehow blocked, but I cannot find any indication to this effect. Any help appreciated, thank you!

EDIT: Sender from third-party is NOTW in my blocked senders list.