check for duplicate emails

Is there a script that will check a non-SQL dB for duplicate emails in Perl or CGI? My Web-app site doesn't use a dB for storing users profiles it only adds them to a CGI-bin db dir.

Is there a script that will check a non-SQL dB for duplicate emails in Perl or CGI? My Web-app site doesn't use a dB for storing users profiles it only adds them to a CGI-bin db dir.
if you can read mails one by one you can compute a md5sum for each and use a hash to store the md5 values.
all you need is to copy the mail each time you see the md5 value is not in hash.
in the end you will have only uniq mails.

best regards