E-mail and templates

Hi
I´m more and more exited about Zoho CRM.
Could you tell me, if I can automaticly add a signature in e-mails sent from the Leads or Contacts.
I would also like to have a template on this place, where I can place my signature and a greeting etc. - just like you can do in the mass mail system.
Can I pay you for having possibility to send more than 250 mass mails? We have about 600 contacts.
Bjarne Ravn