Reopen Service Desk issues when an external participant comments
Problem
A closed issues in service desk do not reopen when a new email comes in. For example see https://gitlab.com/kbychu-apps/service-desk-private-test/-/issues/2
Proposal
For service desk issues, when a new reply from the original external user comes in, re-open the issue.
Other considerations
Resolution
The resolution of the ticket is relevant whether or not this behavior is desirable.
For example, users might want resolved, timed-out tickets to automatically reopen upon a new reply, but not duplicate or spam tickets.
Customizable workflow/automation
This proposal is essentially a type of automation. If we allow people to create/customize their own automation, this should be just a default automation.
Ticket Status
Zendesk distinguishes between solved ticket and closed tickets. Once a ticket is closed, it cannot be "reopened". See more in https://support.zendesk.com/hc/en-us/articles/4408832151834-Updating-and-solving-tickets
Release notes
You can configure GitLab to reopen closed issues when an external participant adds a new comment on an issue by email. This also adds an internal comment that mentions the assignees of the issue and creates to-do items for them.