Exchange 5.5 server and email signature

Hi,

We’d like to have everyone in our org. use the same email signature.
Is there a way to force everyone in your org. to use a single email signature for every email that is sent either internally or externally from
the Exchange 5.5 server?A side from a org. policy or going to every PC with Outlook and changing the signature to what we want it to be. We’d just like to have it show up in their sent email messages automatically.

Thank You.