How to match a string like '+447537170394 <sms at aa.net.uk>' in a send hook?

[Chris Green]

On Wed, Sep 25, 2024 at 10:30:33AM +0200, Francesco Ariis wrote:
> Hello Chris,
> 
> Il 25 settembre 2024 alle 08:50 Chris Green ha scritto:
> > I want to match the following string in a To: address for a send-hook:-
> > 
> >     +447537170394 <sms at aa.net.uk>
> > 
> > The + and < and > have special meanings (I think) in an RE, is there a
> > simple way to tell send-hook that this is just a string with no
> > special meanings at all or am I going to have to escape all the
> > specials?  If I do need to escape them all what do I actually need to
> > put?  Is it just:-
> > 
> >     '\+447537170394 \<sms\@aa\.net\.uk\>'
> > 
> > ... just tried the above, it doesn't match.  So there must be more to
> > it.
> 
> I am sure there is a proper solution, but meanwhile wouldn’t it be
> good enough to just match 447537170394?
> Maybe in your case it uniquely identifies your recipient

OP here.  I think I have found a much more basic problem, I don't
think a send-hook can change the To: address.

So, next question (which replaces the first one), how can I change a
To: header dependent on the contents of the To: header?

What I am trying to do is to change the destination address when I get
messages from addresses like '+447537170394 <sms at aa.net.uk>' because
messages back to that address disappear into a black hole.

-- 
Chris Green