Stop duplicate replies before they reach the customer.

FOUNDATION

Define the support promise before configuring the inbox

Define a default owner or unassigned queue, make assignment visible in the list, show active viewers, keep drafts associated with the ticket and author, and decide when an outbound response changes unread or status state for other agents.

WORKFLOW

Build the smallest reliable operating loop

When someone opens a ticket, broadcast short-lived presence. When they assign, draft, note, reply, or change status, publish the event to other sessions. Keep the latest event ordering stable and refresh data after mutations so optimistic UI never attributes another agent's work to the current user.

PITFALLS

Test the edge cases that break team trust

Presence without expiry creates ghost viewers. Assignment hidden in a detail panel is too late. Polling only the list misses the open thread. Optimistically inventing sender names causes identity flicker. Always reconcile from the server after a write.

CHECKLIST

Validate the customer and agent experience together

Send a new request from an external address, verify ticket creation and acknowledgement, assign it, open it from two agent accounts, add a private note, change recipients, paste an image, attach a file, reply, answer from the customer mailbox, resolve the ticket, delete a disposable test, and confirm a later sync does not recreate it. Record the expected owner and outcome for every step.