My Exchange certificate will soon expire.
We are currently running a Hybrid configuration between Exchange 2007 (On-Premises) and Office 365. Most of our users have been already migrated. Our Outlook email clients are pointing into the Office 365 servers but our MX record is still pointing to our on premises Exchange 2007 box (MX record will be change to point into the Office 365 servers in the next few weeks).
Since, I will say, all my SMTP traffic is handled by the Office 365 servers, do I need to renew the certificate on my on-premises Exchange 2007 server?
If yes why?