If you have a Yahoo account, do not join anything advertising Grouply. It is a phishing scam. It is an e-mail and password hi-jacker for spamming. Basically it will take your account e-mail and password to gather the info of other members of your yahoo group(s) and and spam them. Yahoo is aware of this and will refuse any new accounts using Grouply.
One major problem with grouply is that is makes members only posts publicly available when they should not be–prior to moderator approval of that member. This means e-mail addresses and info written in a group that should be members only suddenly become public–try it searching. You will find you can suddenly read a bunch of posts that you shouldn’t be able to. This how spam gets spread–bots snap up info publicly available.