Looking for a mail-in-> filter->mail-out

I am aware that mhonarc can be used to parse incomining emails and
filter out the "core content" and header.

I do not see a way in mhonarc to send out such content as a new mail
-its generating an html output.

I looked at hotscripts in php and perl but found no script.

Is there such a tool: mail-in-> filter-> mail-out  ?

Thank you for suggestions, Claus