Issue Summary

When a new email is processed by the incoming mail handler, if the user marks the email as unread, Jira processes the same email again and creates a duplicate ticket with the same message ID

Steps to Reproduce

1. Send an email to the incoming mail server and allow the handler to create a new ticket.
2. Once the new issue is created, mark the same email as unread

Expected Results

Jira should not create duplicate tickets as an email with a specific message ID was already processed once

Actual Results

Jira processes the same email again and creates a new ticket in the project using the same message ID

Workaround

Please ensure that the user does not mark the email as unread to prevent duplication