Why multiple cases created by mail with same title?

[Amr Atef]

We have some mail threads results in multiple cases on Jira, I mean for each mail thread, there are more than 1 case created.

And as I knew, there's one case per mail thread so why this may happen?

[Angélica Luz]

Hello Amr,

Thank you for reaching out to Atlassian Community!

Reading the details you provided, it seems that the tickets are getting duplicated.

When a customer creates a ticket, they receive notifications about comments, status, for example, and if they share this notification with someone that doesn't have permission on the ticket and the person replies to this notification, a new ticket will be created instead of adding a comment to the original ticket.

With that said, it's important that the reporter shares the ticket with other customers, so they will also receive notifications and they will have permission on the ticket. If that's the case, the summary of the ticket may contain the "Re", since it's a reply.

If that's not the case, it can be related to an automation that is updating the ticket summary. You can confirm that by going to Project settings > Automation or Project settings > Project automation (if it's a next-gen, Project settings > Apps > Project automation).

Regards,
Angélica