The "Big e-Mails Hunter" application connects to your IMAP account and
searches for e-mails larger than a specified size (in megabytes). It is an
(geek) alternative to http://www.findbigmail.com/ .

The script is written in Python using, solely, the standard language library
[http://docs.python.org/library/] and the IMAP standard
[http://tools.ietf.org/html/rfc3501].

Of course this script can be improved... and you are invited to do it!
(I almost forgot: it is BSD licensed.)