Interestingly, just yesterday this very idea came to my mind. I imagined one more core component though: a content server (think: web server).
Email would serve as a notification/status passing protocol and the actual content would be served by the "embedded" web server.
The imap+content servers could ofcourse be hosted in owned hardware/domain or provided as an ISP service.
Edit: to add more info on my approach:
The content/web server would also host the UI to access/use your social net. I'm thinking of a SquirrelMail plugin as a first attempt, or a GUI overhaul shifting the primary focus to the social net aspect.
The regular email functionality could also be present through a classic looking SquirrelMail interface, so the user can conceptionally separate the email "stuff" from the social "stuff" if he/she needs it.
Email would serve as a notification/status passing protocol and the actual content would be served by the "embedded" web server.
The imap+content servers could ofcourse be hosted in owned hardware/domain or provided as an ISP service.
Edit: to add more info on my approach: The content/web server would also host the UI to access/use your social net. I'm thinking of a SquirrelMail plugin as a first attempt, or a GUI overhaul shifting the primary focus to the social net aspect. The regular email functionality could also be present through a classic looking SquirrelMail interface, so the user can conceptionally separate the email "stuff" from the social "stuff" if he/she needs it.