SquadMail sets up shared email folders that automatically delivers the emails, notes and attachments in that folder to all the subscribers in a group -- making it the "Dropbox of email". Besides group collaboration, you can use SquadMail for your anonymous email needs.
The service works with any IMAP email service, including Gmail, and you can sign up by entering in your IMAP credentials or login through Gmail (SquadMail uses a safe SSL connection for syncing your email and assures us user information is never shared). The service should work with all email clients.
When you set up a shared folder in SquadMail, it is found in your email inbox as a subfolder under "SquadMail". Each shared folder gets assigned a unique email address and any emails sent to that address will be placed in that folder. So, for example, you could set up a folder called "Wedding Plans" for you, your betrothed, your wedding planner and your soon-to-be-mother-in-law, and the email address might be [email protected] You and others can send emails to that address to have them sent to everyone you've invited to that folder, or you can drag and drop emails into the folder to share them. This gets rid of the clumsy mess of fwd:re:fwd email subject lines and wondering who to cc: for every email.
You'll even get a daily digest in your inbox, if you wish, with updates on any new messages placed there, and once you no longer have a need for that email folder (for example, the wedding is over), you can delete it. Any replies sent to messages in the folder are kept there, so it makes organising projects very tidy.
Other use cases include a job applications folder (collecting and sharing applications) and group project folders, but you could also use the app just on your own. SquadMail can be the bridge between your personal account and your work and other email accounts -- drag emails into a folder that will appear on all your email accounts. You can also use the unique email addresses for each folder to subscribe to newsletters, daily deal sites and more. instead of having to give away your real email address or rely on disposable email addresses.
SquadMail is currently in private beta, but the first 2000 Lifehacker readers will be able to register via the link below.