As with the Google Analytics tracking code, all instances of webmaster@eaa.org needed to be changed to webmaster@iac.org, accomplished as follows:
cd /var/www/old-site
find public members -name '*.html' | while read f
do
  echo $f
  ed "$f" << EOFEOF
    g/webmaster@eaa.org/s//webmaster@iac.org/g
    w
    q
  EOFEOF
done
    