Hello,

I have two Exchange 2007 servers (one with CAS/HUB, one with Mailbox) and I would like to set new certificates.

I work a lot with Exchange 2013 but little with 2007, so I have two questions :

• On my Mailbox server, I haven't certificate. I only have one certificate on the CAS/HUB server. This is the functioning of Exchange 2007 ? I don't understand how the mailbox can "talk" with the CAS/HUB in an encrypted way without certificate.
  
• When I will change the certificate on all my services (IIS, SMTP, ...) the clients will have problems with opened Outlook/OWA (certificate errors, reopen Outlook) or it will be transparent ?

Thanks