[Evolution] How to modify a message by external script

[Ambrogio <fn050202 flashnet it>]

Hi all,

I'm writing some script that change headers or body of a messages.

The only way that I know to pass a message from Evo (2.6.0 now) to a
script is to pipe to an external program.

But Even if the script change the message, changes are not used by evo.

There is a way to do so by filter, or I have to write a plugin?

Tnx
 Ambrogio