[Mailmunge] Using $ctx globally.

[list at ptld.com]

> 2) Callbacks that happen in "message contect".  These are all the others
> such as filter_begin, filter_message, filter_wrapup, etc.  These
> ones can call action_XXX methods if they want, and they can optionally
> return a Mailmunge::Response object.  If the *do* return a Mailmunge::Response
> object, then the calling code translates that into calling the corresponding
> action_XXX method.
> 
> So no, you don't need to return anything from filter_message or filter_wrapup
> unless you actually want to reject or tempfail a message by returning a
> Mailmunge::Response object.


Does that include a continue response in the message filter? Does this work? Gets ignored but still works?

   sub filter_message {
     ...
     return Mailmunge::Response->CONTINUE();
     ...
   }