Can't you use the Google calender to send your invitation to a Google Mailing List?

btw: It seems the problems with phplist and hebrew are solved:
http://forums.phplist.com/viewtopic....ghlight=hebrew
If phplist's import doesn't work for you, you can import the mailadresses with a tool like phpMyAdmin directly into the database tables from phplist. It's easy:
http://forums.phplist.com/viewtopic.php?t=6553

Regards,
Remi