How can I write a procmail recipe to execute script without affecting the original message

Question

I want to use procmail to trigger a script to run when a certain email message is encountered but I do not want to change, alter, or prevent delivery of the original message.

Will this procmail recipe work?

    :0 fw
    * ^From: .*numbchild@gmail\.com
    {
        :0 c
        * ^Subject:\/.*
        | /bin/sh $HOME/bin/notify.sh "Thread ('$MATCH') updated" "Body"
    }

Answer 1

From the manpage:

   c    Generate a carbon copy of this mail.  This  only  makes  sense  on
        delivering  recipes.

So yes, the c flag will cause the message to also be delivered with the next matching recipe.