EPiServer Mail and Community are, at least for now, internally using a separate user database part of EPiServer Common.
The EPiServerCommonMembershipProvider is a regular membership provider based on this user database.
The EPiServerCommonIntegrationMembershipProvider (and the related multiplexing integration provider) are wrappers that on successful authentication in the underlying membership provider makes an entry in the EPiServer Common db.
This is where the roleToSynchronize comes into play, you can filter which roles make users candidates for being copied, but it can be left as "*".
For some setup info on the integration providers, you may want to look at this: http://blog.tomstenius.com/2009/04/episerver-community-role-and-membership.html
Before we did the upgrade to R2 and EpiServer Mail 4.4 there was a simple administration panel for EpiServerMail at /Netstar/admin if I remeber correctly. But after the upgrade we had to use the EpiServer.Common hotfix to be able to use the Mail functionality.
But where did the user administration go? I'm having serious problem understanding how to configure which users get access to Mail and who don't.
Trying to find information on the new EPiServer.Common is quite hard. What do the roleToSynchronize do for example? And why does the combination of our custom membership provider and the use of EpiServer.Common cause the server to fault the w3wp process several times a day when there was no problem with the EPiServer.Security provider?
And whats the difference between EPiServerCommonMembershipProvider andEPiServerCommonIntegrationMembershipProvider
Anyone who can shine some light on this?