ReSubj is a place to start a discussion with your friends or colleagues or anyone. These people don't need registration (neither do you) or accounts on ReSubj. You only need to know their emails.
After you collect emails in a recipients field, write your message and hit “Create an inbox”—you'll be redirected to your newly created Inbox. At ReSubj an Inbox is a page that contains your discussion. Recipients will be able to access an Inbox page, read your message and post their own comments. They will also receive email notifications and will be able to post new comments simply by replying to those notifications in their email client, without visiting the Inbox page.
We think Google Wave will be a great tool. And we think we'll make it easy for ReSubj users to integrate with it. Yet, we provide a working tool for communication that works for anyone who has email account anywhere. ReSubj goal is that you don't have to worry whether recipients have accounts at a specific service.
We're constantly watching the spam situation and use the most unobtrusive means to prevent spammers from using our service for sending their messages. We also have a limit of 100 participants per inbox, which will be altered to a bigger number in the future depending on user requests and necessities.
Check our FAQ page to find out more.