Most people think of e-mail, when they see a user address. As we have user addresses for all of Chat, remoteStorage (soon), Social (not LDAP yet), and possibly other services in the future, it was proposed during the recent Summit that we should set up some kind of e-mail service.
The most simple version would be just a forwarding service, so that when someone sends e-mail to your Kosmos user address, it gets forwarded to the address stored in your LDAP/Accounts profile.
The more advanced version would be a full-on e-mail service. This could either be self-hosted by us, which currently no active contributor wants to be responsible for. Or we could partner with a decent service provider for that. For the latter case, the name Posteo was mentiioned.