"Your Mail is Rejected" Notification

Summary:

Currently, when JIRA process an email in the configured mail handler, it is either create a new ticket in the instance or silently reject the mail with some information written in the logs. Hence, it will be great if there is a notification to the sender if their email is rejected, such as how when an user is not allowed to access a certain page in JIRA.

Steps to Reproduce:

1. Configured JIRA Incoming Mail
2. Make sure that the "Create Users" function is disabled
3. Send an email to the Incoming Mail Address as an Unregistered User

Current Result:

• JIRA will process it and mark it as read, but the ticket is not created. The information why will be found on the logs.

Desired Result:

• JIRA will process it and mark it as read, but the ticket is not created. There will be a notification to the sender that the email has been rejected.

Note:

• This should apply to JIRA Service Desk Mail Handler as well.