to hook script

[Albert Shih <Albert.Shih@xxxxxxxx>]

Hi all

How can I write a "to hook script" ?

For example :

        When I send a mail to X I want modify my From field
        When I send a mail to Y I want modify my Reply_to field.
        etc.

Thanks.

--
Albert SHIH
SIO batiment 15
Observatoire de Paris Meudon
5 Place Jules Janssen
92195 Meudon Cedex
Heure local/Local time:
Mar 18 mar 2008 14:38:27 CET