development of a software: extract data fields from email-files

I require a script that extracts data from emails stored on a local PC. These mails have been downloaded from the email client Thunderbird and are stored in a dedicated folder. The PC is running under UBUNTU Linux. The emails have an identical structure (See example). The relevant data is to be found in the enclosed files: Each mail got ONE zip-file (containing a HTML-file with the data I require to extract) and MANY jpg-files. I need the content (=data fields contained in the HTML-file) of all these mails beeing extracted and stored in one common CVS-file. The jpg shall be copied into a common folder. The software solution should be easily runable on my UBUNTU desktop. Additional Information given: 1. Presentation with datails of the data 2. A sample of such email-file