Can you believe that ? If not believe it. I invited a friend of mine to join a group and the invitation went to his gmail spam folder.

Now it looks like their spam finding algorithm is very neutral and is not giving any special consideration to the mails from google servers itself.

Google has one of the best spam fighting technology. But some times google also makes mistakes. There are still many spam mails in my inbox, most of them are the popular multi million dollar African fraud mails. There are some lottery mails also.  Google is still unable to detect them.