If you're receiving duplicate messages from a Google Group, first, try these troubleshooting tips:
- Make sure you're subscribed to the group in question with only one email address. If you have a second email address subscribed to the group, try unsubscribing one to see if this resolves the problem.
- If you have email forwarding set up on one of your other email accounts, make sure that this other email address isn't forwarding emails to your current address. If this is the case, unsubscribe the forwarding address from the group.
- If you have only one email address subscribed to the group, unsubscribe, and then re-subscribe that address.