Digs mail log files matching sender or recipient
Perl
Copy the file dig_mail_log to /usr/local/sbin or another place in root path.
# dig_mail_log --to=someone1@example.com
# dig_mail_log --from=someone2@example.com
# dig_mail_log --to=someone1@example.com --from=someone2@example.com
# dig_mail_log --to=someone1@example.com --verbose
# dig_mail_log --to=someone1@example.com --file /var/log/mail.log.1