CryptoHeaven allows you to have a discussion with a single or multiple partners in a secure environment.
Anyone on your contact list can be invited to participate. To invite people to participate in your discussion, select Folder Properties->Sharing from the folder pop-up menu. Make sure the Share this folder option is selected, then press the Add button to invite others.
Your messages may include file attachments.
To compose a new message click on theicon located on the toolbar.