Michael,
Resolving a bounce condition requires action on the member's side of things.? They or their email provider have to do something so that the provider does not bounce incoming emails sent from groups.io.
Until that is done, bounce probes are useless (other than proving the messages are still being bounced).
There is good explanation here ->?
/g/GroupManagersForum/wiki/Help-Mock-up#Bounce-HandlingThe member sending an email to groups.io would not do anything as groups.io cannot do anything about the member's email provider that is bouncing the emails.
Thanks
Toby