Group bounces messages from disabled account
If messages to a Google Group bounce, this may be because the sender's account has been disabled. To confirm if this is the cause, check the email logs. If the messages bounced because the sender's account had been disabled, the email log should display information similar to this:
|firstname.lastname@example.org June 28, 2013 10:40:42 AM||The account email@example.com is disabled|
To resolve this issue, the user of the disabled account must re-enable the account by logging in with their account credentials ('firstname.lastname@example.org') at https://accounts.google.com.
Note: This can occur even with a message from an external sender if that sender has a disabled Google account with the same email address.