Troubleshoot Rejected, Duplicate, Automatic, Bounce, Loop, or Failed Inbound Email

This article covers deduplication, auto/bulk/bounce filtering, unauthorized sender handling, read failures, processed-folder/seen behavior, and mailbox diagnostics.

Where this fits in QC Support Ticket

Inbound email is a Max/All Access feature. Each enabled mailbox connects to an ordinary IMAP account, routes new tickets to one Department, can accept replies to existing tickets, and can process attachments and supported Agent commands according to the mailbox settings.

Inbound processing is intentionally defensive: it checks sender authority, ticket identity, deduplication, loop/bounce/automatic-message signals, attachment policy, and mailbox state before it changes ticket data.

Primary location: Joomla Administrator → Components → QC Support Ticket → Email Templates → Inbound Mailboxes.

Before you begin

  • Confirm the site currently has Max / All Access effective access before expecting the controls described here. A preserved configuration may still exist after downgrade even when the feature is locked.
  • Confirm Joomla Mail works before diagnosing QCST template delivery. For inbound mail, confirm PHP IMAP is available and keep one controlled test message available.

Troubleshooting procedure

  1. Run Test first to separate IMAP/TLS/login errors from message-processing errors.
  2. For a message that is skipped/rejected, inspect whether it is a duplicate message, automatic/bulk/bounce/loop candidate, unknown/unauthorized sender, or lacks valid ticket identification for a reply.
  3. Check attachment-policy rejection separately from message-body/routing failures.
  4. Review whether the message was marked/moved according to the configured failed/processed-folder behavior so the same bad mail does not loop indefinitely.
  5. Use Process Now and the safe mailbox diagnostics with one controlled test message after each correction.

Important behavior and limits

  • Do not include IMAP passwords or full private mailbox content in screenshots/support posts; use QCST's sanitized diagnostics.

Verify the result

  • Mailbox Test succeeds before unattended processing is relied upon.
  • Process Now handles one controlled message exactly once and records a safe result without duplicate ticket/reply creation.

If it does not work as expected

  • If connection fails, verify PHP IMAP, host/port/encryption/certificate settings and credentials before changing routing.
  • If connection succeeds but processing fails, inspect sender policy, ticket reference matching, duplicate/loop checks, mailbox capabilities, and attachment policy.

Community Discussion

For practical QC Support Ticket workflows and discussion with other Joomla site owners, visit the QC Support Ticket Community. For private support, bug reports, account-specific issues, or feature requests, use the QuantaCade support system.