Hi Doug, we get this problem all the time as well, especially from 3rd parties who use their own email templates, and we end up with loads of duplicate tickets.
This thread has some info about how FS checks emails: https://support.freshservice.com/support/discussions/topics/308918
but the ticket ID actually needs square brackets - so #INC-3] - in the subject, but because the message ID doesn't match we don't get great results from it, even with the proper ticket ID in the subject.
Thanks Jonathan for sharing the corresponding details to Doug.
Doug, please do try out the solution suggested in the previous topics shared by Jonathan and let us know if you need further assistance on the same.
Thanks,
Raj
Very sorry, the solution did address my question, thanks please close ticket.
Thanks for the update Doug, please do reach out to our support team for any assistance.