SPUG: Regex that matches everything except a specific string

[Richard Anderson]

I am trying to feed a regular expression to a mail processing program that
matches every string except a specific string.  For example, I want a regex
that does not match richard at richard-anderson.org but matches any other
string.  If I were writing a Perl program, I would just do this:

if ($address !~ /^richard\@richard-anderson\.org$/) { print "Spam\n" }

but I am not able to modify the source code of the program I am using.

I haven't been able to do this using the complement metacharacter (^).  I'd
accept a solution that matches anything except an anagram of
richard at richard-anderson.org

P.S. This is actually a Python regex, but Python's regexes are very similar
to Perl's regexes.

Richard Anderson
richard at richard-anderson.org
www.richard-anderson.org
Richard.Anderson at raycosoft.com
www.raycosoft.com