[Dovecot] trying to enable features

Hello all, I'm trying to enable 3 different features in my mail system (postfix, amavisd, dovecot).

1)out of office auto reply 2)script execution based on email 3)automatically add disclaimer/signature to outgoing email (also listed in order of importance to me)

I'm looking for pointers to documentation or instructions. It seems that 1 and 2 would best be done in dovecot somewhere, while 3 is probably best implemented in postfix. (my next step is postfix documentation)

Can anybody provide any suggestions or pointers to a how to or other documentation? Thanks, Ray