formail question

The following line in the mail header:

             Content-Type: text/plain; charset=iso-8859-1

causes my elm not be able to display the mail:

             sh: metamail: not found

I want to use:

       :0 fhw
       | formail -I Content-Type:

to take out the line in the header.  But how shall I let it pass the
mail on to the rest of the procmailrc recipes?

Thanks in advance!

Zhiliang