Question
What happens to the tickets of user after they've been deleted?
Answer
The following outlines how a user's deletion from a given account affects the tickets they've interacted with:
Tickets assigned to the deleted user (for agents)
The agent will be removed as assignee and the tickets will be reassigned to the agent's group:
For more information on deleting agents, see the article: Best practices for removing agents.
Tickets requested by the deleted user
A user cannot be deleted if they are still listed as the requester of any un-closed tickets. If you try to, you'll get an error indicating that, User is requester on [x number of] tickets that are not closed.
If you open up one of the deleted user's closed tickets after they've been removed, you will not be able to view their user profile by clicking their name. Doing so will bring you to an Oops page since they no longer exist on your account:
Tickets the deleted user is CC'd on
If the user is CC'd on any un-closed tickets, they will be removed from the ticket. It's important to note, this will not be recorded as an event on the ticket in the way removal of the assignee on a ticket is in the events log.
For more information on deleting users, see the article: Deleting users.