Question : Overwrite existing default SMTP certificate on Exchange 2007

I want to apply "Enable-ExchangeCertificate -Thumbprint..." to my Exchange 2007 server but when I run this script through Exchange Management Shell, it show me a message to confirm that do I want to overwrite the existing SMTP certificate...

The default cert is pointing to my local server name, but I have another thumbprint that is pointing to the host name of OWA URL.

Thumbprint                                     Services            Subject
21KLJH24297DAS23......               ....S                   CN=EXSERVER
JH3453987SKDFAHS2,,,,,,             IP.WS                CN=webmail.mycompany.com OU=Domain Control....

Do I need to overwrite the existing default cert when I run the following command?  What happened and does it affect any after overwrite?
Enable-ExchangeCertificate -Thumbprint JH3453987SKDFAHS2........ -Services "SMTP"

Answer : Overwrite existing default SMTP certificate on Exchange 2007

It would not affect anything other than SMTP.

use Enable-ExchangeCertificate -Thumbprint JH3453987SKDFAHS2........ -Services "SMTP" ; restart transport service and you would  be good.

The important thing to note is that you have Common name  for the cert ( webmail.mycopanyname.com) = hostname of the box. else it won't work unless you have UC SAN certificate with hostname as an additional name in the cert.

 Thx