Enable-ExchangeCertificate -ThumbPrint [xxx] SMTP, IIS, POP IMAP

[John.Leonard]

After importing this cert from a CA - I go to enable this and get the WARNING
that I am about to over write the existing SMTP cert and that TLS will not
work???

WARNING: This certificate will not be used for external TLS connections with
an
FQDN of 'mail1.mymail.com.COM' because the self-signed certificate with
thumbprint 'AAA-THUMBPRINT-AAAAAAA' takes precedence. The
following connectors match that FQDN: Default MAIL1, Client
MAIL1.
Confirm
Overwrite existing default SMTP certificate,
'AAA-THUMBPRINT-AAAAAAA' (expires 1/01/2XXX 2:23:15 PM),
with certificate 'XXXXX-THUMBPRINT-XXXXXX' (expires 2/XX/2XXX
12:34:13 PM)?
[Y] Yes [A] Yes to All [N] No [L] No to All [S] Suspend [?] Help
(default is "Y"):

We want to use it for external TLS - that is the whole reason to go this....
it has been suggested that this link will help - it was more confusiton.

http://technet.microsoft.com/en-us/library/bb430748.aspx

I want to keep my existing default cert - just in case - what are the
commands that I can use to even push it down in the "priority" if needed and
use the CA cert as the primary and the default as secondary - - or...... copy
it or disable so that it is safe?

Thanks in advance for help.

-John