Need help writing predicate function

[Max Evans <visitantar@protonmail.com>]

Help, gnus!

I'm trying to write a simple predicate function to use in my
posting-styles, since from my reading of the manual you can't match
two things at once otherwise, which is what I want to do.

I'm trying to make a rule that kicks in only when a certain company
sends me an email AND when it's sent to a particular address. It's
only relevant when I'm replying back to them, though.

Here's what I've got so far:

(defun max-gnus-predicate ()
  (when (eq major-mode 'gnus-article-mode)
    (and (string-match "foo@bar.org" (with-current-buffer gnus-article-buffer
				       (message-fetch-field "from")))
	 (string-match "visitantar+alias@protonmail.com" (with-current-buffer gnus-article-buffer
							   (message-fetch-field "to"))))))
						 
The problem I'm running into is that the function fails if the
*Article* buffer ever gets killed. When that happens, it corrupts the
mail header. Which makes sense with how I've written it.

I'm sure there's a smarter way of doing what I want to do, so would
someone mind helping me out?

(Please keep me in the thread. I'm not subscribed.)

-Max