A while back I tested Group Calendar feature. It worked on client and web. A lot of changes have occurred since then and now there is interest in using this feature once again. I am sorry I have not been involved in making most of these changes so I don't know what the changes have been.
Currently, the problem is that most of our users are on iNotes Web Access v 6. When they try to open Group Calendar view it never opens. However, when opening their database from Domino the group calendar works fine.
I have tried to determine the problem....one thing I did was to change the setting for:
"SMTP allowed within the local Internet domain" from 'All Messages" to "Disabled". I have not noticed any favorable or unfavorable results from making this change.