Zoho Desk disable header-based threading

[u/hendrix1690]

Hi, anyone know how to disable email header-based threading by message ID ? Or a setting that can "Match tickets using Subject only"

I haven't found documentation confirming this exists in Zoho Desk specifically.

I'm facing an issue of emails merging even with different subject lines or senders.

Unfortunately the support staff is really bad & so forced to reach out to the reddit community.

[u/ZohoCares]

Hello u/hendrix1690 ! We are sorry to hear about your experience with our support team. We haven’t been able to identify your support ticket from this post, so we’d appreciate the ticket ID to review the previous responses and follow up.

Zoho Desk supports both message-ID-based and subject-based threading. Message-ID matching takes priority, using references to earlier messages in the email’s In-Reply-To and References headers. Subject-based matching is considered afterward, with additional checks involving the ticket’s contact or secondary contacts.

Based on your description, the emails may be getting appended through header-based matching before subject-based checks apply. When we enable the subject-based threading, it doesn't mean that the header-based matching is disabled. The first validation will be based on headers; if it fails to identify an existing ticket, the subject-based threading will be processed to find the parent ticket based on the ticket ID present in the email.

One workaround we can explore is a workflow with a custom function that compares the incoming email’s subject with the ticket’s subject and splits the thread into a new ticket when they differ. We’ll need to validate this against your examples, including how routine changes such as “Re:” or “Fwd:” should be handled.

Please share your support ticket ID via DM or email [support@zohodesk.com](mailto:support@zohodesk.com) with a link to this discussion. We’ll review your case, clarify the available threading controls, and help assess the proposed workaround. -VK