Jira Service Management creates duplicate tickets for emailed requests

Summary

E-mails sent to the Jira Service Management connected email account create two requests in the project for the same message and don't provide any error in the logs.

Steps to reproduce: 

1. Create a forwarding rule in your mail provider pointing to the default incoming mail <something>@<instance>.atlassian.net

2. Connect the same email that has been set to forward as a custom incoming mail (Add a custom email account)

For example, messages sent to support@provider.com are automatically forwarded to the default incoming mail <something>@<instance>.atlassian.net, but support@provider.com is also connected with the project.

Diagnosis

• Each message sent to the custom email accounts generates 2 tickets in the service project

• Downloading the message that generated each ticket from the email logs (View the email processing and connectivity logs) confirms it's the exact same message (headers contain the same message ID).

Cause

Creating a forwarding rule that involves the same email account that is connected with the project's email channel causes messages to be processed twice, once by the custom email account, and once by the default email account when it receives the forwarded message. Jira can't prevent these duplicates as the whole process happens instantly.

Solution

Possible options:

• Disconnect the custom mail handlerand use only the forwarding rule so when the user sends a message tothe forwarding mail it'll be properly forwarded to the default mail and then create the request; OR

• Delete the forwarding rule and use only the custom email connected with the project, leaving the default mail without use. By doing this, all requests will be sent and processed directly bycustom email.