[imp] Dynamic mailer config based on FROM and TO addresses

[Robin Bankhead]

Hello,

I am hoping to use Horde/Imp (latest horde-webmail from PEAR) with  
Apache James v3 (eternal beta) as IMAP server and local delivery  
agent.  The local mailstore will be receiving mail from a number of  
domains/accounts, but it has no true FQDN of its own, so everything  
gets fetched into a single @localhost IMAP mailbox.  That IMAP login  
is set to autologin in horde main config, and Imp uses it via  
$servers['imap']['hordeauth'] = 'full'.

The James SMTP server *could* relay all outgoing mail for all these  
domains, but in my testing this has garnered high spam scores, even  
when clients are locally doing SMTP AUTH.  I guess this is because of  
our lack of an originating FQDN.

I'd therefore like to have Imp choose the SMTP server config  
dynamically upon sending, based on both From: and To: addresses of the  
outgoing message.  The user would choose the From: address using a  
list of Identities defined in global prefs.  The

The things I need to know are:

1. Can this be implemented at all? (I reckon it can, but...)

2. Would I implement it by a routine in one of the conf files (I have  
done it like this before, for turba config circa H4) or would I need  
to use a Hook?

3. Where do I find the variables I need for
  (a) The From: address or Identity, and
  (b) the To: address?

Very grateful if anyone can steer me a little towards this goal.

Robin Bankhead