grep

grep 'Esta newsletter foi enviada para' 2.html|grep -E -o "\b[a-zA-Z0-9.-._]+@[a-zA-Z0-9.-]+\.[a-zA-Z0-9.-]+\b"|sort -u|wc -l

este é melhor:
grep -o '[[:alnum:]+\.\_\-]*@[[:alnum:]+\.\_\-]*' Delivery_Status_Notification__Failure_.mbox | sort | uniq -i > emails.txt

http://www.thegeekstuff.com/2011/10/grep-or-and-not-operators/

grep -r "modules" .
grep -lr "modules" .

http://blamcast.net/articles/recursive-grep-find-strings-files