If you are getting more notifications than you want, remember to set how you want to be notified under the SUBSCRIPTION tab on the left in Groups.io.
The choices are:
Individual Messages: You will receive each message in an individual email.
Full Featured Digest: Group up to 12 messages together as one email instead of being sent individually (rich formatting).
Plain Digest: Group up to 12 messages together as one email instead of being sent individually (plain formatting).
Daily Summary: A daily summary, delivered in the morning, of the group's messages from the previous day.
Special Notices Only: You will only receive special notices from the moderators.
You may try different settings until you find the one that works for you. Also, you can change how notifications are delivered to each Groups.io subscription.