Certificate Question?

[cyber7]

Hi Guys.
I am using ZCS 6.0.10 (paid release) and have a question regarding my certification. To understand my problem/delema, I have to give you my configuration:

1. Connection: INTERNET<->FIREWALL<->ZIMBRA
2. ISP sends mail to MAIL.EXAMPLE.COM (Zimbra)
3. BUT, from the internet MAIL.EXAMPLE.COM points to a FILTER SYSTEM.
4. I call ZIMBRA with MYMAIL.EXAMPLE.COM from the internet.
5. ZIMBRA runs on a SPLITDNS.

Now for my question/problem:
when I create a certificate, do I use *.example.com or mail.example.com or mymail.example.com?

Points:
When creating mymail.example.com and calling it from inside my network, I do not get a CERT ERROR, but calling it from the internet gives me a cert error.
I have created a VIRTUAL HOST called MYMAIL.EXAMPLE.COM in ZIMBRA.

Please help
Kind regards
Aubrey Kloppers

[jummo]

You can use Subject Alternative Names.