Fetchmail

poll my.pop3.server
protocol pop3
user 'myuser'
password 'mypassword'
mda '/usr/bin/procmail -d %T'

:0
*^content-Type:
{

   # backup the complete mail first..
   # you can leave out this part if you don't want a backup of the complete mail
   :0c:
   $HOME/mail_backup

   # Now the actual unpacking part
   # forward to uudeview and unpack attachments to $HOME/attachments
   :0fw
   | uudeview -p $HOME/attachments -
}