In a time when email addresses did not always make sense, email signatures served the purpose of identifying the author to the recipient. As described in RFC1855 (Netiquette), it had to be short and to the point. Evolution has since driven the feature of signatures into new functionality and areas, like marketing and legal recognition. Today many organizations has strict rules for signatures, the content and the format, and some countries demand business mails to have certain text and statements included in the signature.
Kolab has an option to automate this feature, so that organizations can be assured that rules and appliance are followed.