In some legislations it is obligatory, to send certain company information with every business email, such as the tax number etc. Because having this long stuff in the signature is ugly, I prefer to attach a vcard ("vcf") file with all emails. This can be easily ignored by most and easily used by some.
How can I attach a file to every outgoing email? It is OK, if the file is always the same for all users of the same company. (My setup is one-company, btw.)