I have setup the mandatory signature according to the appropriate lines in the admin guide with a little help from the forum.
all works fine for mail send from the webconsole and all recipients can see our signature.
however: when clients use third party mail software like outlook, apple mail, etc, the signature is not added to the outgoing mail.
Does someone know why this happens?

we are using Zimbra 7.1.1 on Ubuntu 10.04 server.

I hope someone got the answer, regards, Fons