Report of email received by mail.protection.outlook.com for an on-premise mailbox

Hello,

We used to have an on-premise Exchange server that received email through an O365 connector.  The MX record for the email domain was (as I understand it) and currently is [domain-tld].mail.protection.outlook.com.  That is to say, I believe it always received inbound mail via Exchange Online Protection.  The on-premise server has since been decommissioned (before my time) and its mailboxes moved to M365.

How can I obtain a report of all messages received by mail.protection.outlook.com for a particular mailbox sent by a particular outside sender?  This report must include messages that were received prior to the mailbox's existence in M365, i.e. when it was still on the on-premise server.

Thank you