How are the private group invitations (email) supposed to work? I sent one to one of my email addresses, and it has a link in it, but when i click the link it takes me to a login page if i am not logged in, and the group listing page if i am logged in.

What is supposed to be happening?

What about if the email is going to a non member?

The invitation to a member worked great, but they are already members of the site. the email invitation seems important when getting going.

Is there a url that a private group owner could give out that would have a way for someone to request to join the private group?

I'm a little confused on invites as well. Not just for private groups but for all non members. It seems like there should be a simple process to allow group owners (and eventually other members) to invite members and non-members easily.

Has anyone ever figured out how this is supposed to work?  As far as I can tell, the private group invitation email just contains a regular group URL.  There's nothing special about the URL to indicate that it's granting access to a private group.  If I try to use the email link either before or after logging in I just get redirected back to the group directory.   And since the group is private, it's not listed there.  

The link should contain a query string parameter like gcode/1234/. When AS detects this in the url it will add the current user to the specified group. If you get a login page while following the group, you are supposed to be added to the group after successfully logging in.

OK, but we're not getting any query string in the private group invite email, just a normal group URL like http://www.company.com/groups/group...g/30.aspx. Any idea what the issue might be?

Yes, it looks like you are using a url rewriter. The URLS should look like this by default: /SocialGroupDirectory/SocialGroupDetails/tabid/92/asg/3/Default.aspx

Thanks, that pointed me in the right direction. Turns out there were a couple of problems:

1) The email template for invite emails was using [AS:GROUPINFO:GROUPURL] to specify the URL. Changing this to [SITEURL] generated the correct URL with the gcode parameter attached.

2) We are using iFinity URL Master to rewrite urls, and this was forcing the resulting URL to lower case. This resulted in an error when the user tried to use the email link and join the group. When you use the invite link, it creates a "gc" cookie with a value like "123G45A6789". With lower case URLs enabled the cookie value was being set to "123g45a6789" which the module wasn't able to read because it is case sensitive.