[drhughes]

I have three mailbox servers (Made up names and IPs):
mailbox1.domain.com 192.168.10.1
mailbox2.domain.com 192.168.10.2
mailbox3.domain.com 192.168.10.3


My DNS is setup as the following:
mailbox11 IN A 192.168.10.1
mailbox12 IN A 192.168.10.2
mailbox13 IN A 192.168.10.3


I have proxy turned on for all three mail servers. Then I setup a domain called:

mail.domain.com

The DNS entry:
mail IN A 192.168.10.1
IN A 192.168.10.2
IN A 192.168.10.3


I can get SSL working fine on all the individual server, but it is unclear how I get SSL to work on my domain (mail) without the browser throwing a security error.

Do I need to get three certs (mailbox11, mailbox12, mailbox13) or can I get one cert for the domain (mail) and add it to all three servers?