Re: Need help writing predicate function

[Bob Newell <bobnewell@bobnewell.net>]

I do something similar to change identity and/or input
language based on addressee.  I just put it in a hook
  
(add-hook 'message-setup-hook 'rjn-change-stuff-by-addressee t)

and that works for me; the appropriate identity gets chosen
via gnus-alias-use-identity when the message reply is set up.

My complete code is this.  It is not the same as you ask but
easily modified.  You'd only need the upper half.

(defun rjn-change-stuff-by-addressee ()
  (interactive)
  (let ((addressee (message-fetch-field "To"))
	netaddr person smtppref)
    (if addressee
        (setq netaddr (cadr (mail-extract-address-components addressee))))
    (if netaddr
          (setq person (car (bbdb-search (bbdb-records) :mail netaddr))))
    (if person
        (setq smtppref (bbdb-record-field person 'smtp)))
    (if smtppref
	   (gnus-alias-use-identity smtppref))
    	      ) 

  (let ((addressee (message-fetch-field "To"))
	netaddr person langpref)
    (if addressee
        (setq netaddr (cadr (mail-extract-address-components addressee))))
    (if netaddr
	(progn
          (setq person (car (bbdb-search (bbdb-records) :mail netaddr)))))
	    (if person
		(setq langpref (bbdb-record-field person 'language)))
    (if langpref
	(set-input-method langpref)))
  )

-- 
Bob Newell
Honolulu, Hawai`i

- Via GNU/Linux/Emacs/Gnus/BBDB