I have configured a group inbound email account, a group outbound email account and a bounce account.
When logged in as admin, I can view all email inbound accounts and send from the outbound account.
When logged in as a standard user, I cannot view the inbound email accounts or send outbound emails. When I view the access tab in the user profile, I can see everything is green and either Enabled or set to All.
I have not created any roles or security groups yet.
The group email account and the user must be in the same security group if I remember correctly for group emails.
Also this has been broken for quite some time. I posted a fix on Github that I don’t think was ever merged. So it may not work. The issue at the time was only Admin could see group folders. That was a few years ago so not sure if another fix has been implemented since then.