Why I keep receiving mails from this group?

I know I am using VIM and may visit this group once before. But now it seems I am in the mailing list of this group while I don’t know how to unsubscribe.

Could anyone tell me how to remove me from the mailing list? No offense this group is a good source for my daily vim using but I just don’t want to receive so many mails.

 

Thanks a lot