People ask to join our main group in several ways - through Groups.IO, through word of mouth, some books or other web sites list us as a resource (we are a peer support group). No matter how the referral comes to us, we have a "form letter" that is manually sent by one of the moderators - we have shifts so 4 of us can take turns checking our group email account and the Pending member list. Our letter tells a little more about the group and includes the questions we want to ask of new members. AFTER we get a response to that email then we "Approve" or "Add" the member and they get the automated Welcome Letter through Groups.IO.
It really isn't that much of a problem - we only get a few inquiries a week now (after over 20 years the size has leveled out!) and our form letter is stored as a template so our "check the email" chore usually takes only a minute or two. I can see wanting to automate this if you get dozens of requests, or if you are the only person responsible for it, but actually, we like to have that bit of personal contact before adding a new person.
I know there are lots of ways groups have handled the issue of needing more information or verification - just sharing what works for us.
Barb
