Notification contacts
An email address that belongs to a project, a team or the organization, rather than to a person, receives each action-required item raised in that scope, which is also how the inbox reaches a Slack channel.
The address belongs to the scope, so it keeps receiving after whoever set it up has moved on. Each item sends one short email: the item, the project, and a link back. The subject line carries the whole thing. The body never contains document contents, findings or code; the detail is behind the link, signed in.
Slack gives a channel an email address, and that address is a valid contact. One channel for everything is an organization contact, one per team is a team contact. The levels add up: a project's item reaches the project's, the team's and the organization's contacts, and an address present at more than one level is mailed once. A project or team lists what it inherits from above, read-only. Anyone who can edit a project sets its contacts; team and organization contacts are for owners and admins.
Nothing is sent to an address that has not confirmed. Adding one issues a single confirmation link, good for seven days, and until it is opened the contact receives nothing. Opening it signs nobody in and grants no access. An address that bounces or reports spam is marked Suppressed and stops receiving, and the contact says so. Every change is recorded in the audit log.
Removing a contact stops delivery at once, queued items included. The inbox remains the record of what needs a person; a contact is a way of hearing about it elsewhere.