Re: Group settings
I don't think you can change that by sending an email, but you can follow these steps:
1. Go to https://groups.io/sendloginlink and enter the email address that you are subscribed with.
2. Once you receive it, follow the login link in that email.
3. Select the group (eg flicktype alpha or beta).
4. If on mobile: Bottom right of the screen "More", then Subscription. If on laptop or desktop: "Subscription" on the right sidebar.
5. Change the "Email Delivery" option.
I should also note here that there's plenty of settings to customize from the web interface, as well as the ability to access all the message archives.
Hope this helps!