i have a Exchange 2019 server on the LAN and a reverse proxy (IIS). Until now, my company was using a wilcard certificare from Certigo.
we're planning to use Let's Encrypt so i've read a lot of documentation and i plan to use win-acme in order to install the new certificate (the wilcard will expire in a month).
Let's say my domain is example.com and my mail server webmail.example.com. If i install a certificate on my mail server does it mean that i will have to use the same certificate on our web server (www.example.com) and on my reverse proxy? Or does the certificate will only be valid for webmail.example.com and autodiscover.example.com ?
Can i just ask for a different certificate an all my server (web, mail, etc...)? How about the reverse proxy ?