Configure Inbound Email Attachment Limits
This guide shows allowed extensions, max MB per attachment, max attachment count, and how inbound files are revalidated before protected storage.
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.
- Review the site-wide attachment size and extension policy first; field/mailbox-specific limits can be stricter but should not be expected to bypass the global protected-file rules.
How to do it
- Edit the inbound mailbox.
- Set Allowed attachment extensions, Maximum MB per attachment, and Maximum attachments per email.
- Keep the list narrower than “everything”; executable/active content remains unsafe even if a sender renames it.
- Save and test one permitted attachment plus a disallowed/oversized case.
- Open the created/replied ticket and confirm accepted attachments are stored as protected QCST attachments.
Important behavior and limits
- Never loosen attachment rules merely to make an unsafe file upload succeed; use a safe archive/alternate transfer method when support genuinely needs a blocked file type.
- Do not include IMAP passwords or full private mailbox content in screenshots/support posts; use QCST's sanitized diagnostics.
Key fields and behavior
| Item | Current behavior |
|---|---|
| Allowed extensions | Default mailbox list: jpg,jpeg,png,gif,pdf,txt,log,csv,zip,doc,docx,xls,xlsx |
| Maximum MB per attachment | 1–100; new mailbox default 10 MB |
| Maximum attachments per email | 1–25; new mailbox default 5 |
| Global safety | Mailbox limits do not make dangerous active/executable types safe and do not bypass QCST protected storage |
Verify the result
- An allowed test file within size limits uploads and downloads through the authorized ticket path.
- A disallowed extension or over-limit file is rejected without becoming directly web-accessible.
- 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 upload fails, compare the file-field/mailbox limit with the global attachment maximum and extension allowlist; also check MIME/type validation.
- 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.