graeme_p - 7:58 pm on Apr 15, 2011 (gmt 0)
If its just a matter of parsing local email and extracting the attachments, you can probably do this with any of the major scripting languages. It looks to me like the email package in the Python standard library can do it for a start. Write a script, call it with a cron job.
You may be able to do it using the nmh command line email tools. I am not familiar with them, but the functionality to extract attachments exists.