Issue Summary
When a user sends an email to JIRA email handler and the email contains an issue key of an existing JIRA issue in another project, JIRA would simply add a comment to the existing issue(depending on how project permission was configured) but no notification is sent to the user letting them know that a comment was added to the existing issue.

• Create new project and an issue in JIRA.
• Send an email through a mail handler configured for another issue however ensure that the email contains the issue key:

  If an email message contains an issue key in its subject line and that issue key exists in your JIRA installation, the handler will add the email message content as a comment on the issue, regardless of which project the issue is in.
  

• However no notification is sent to the customer to let him or her know whether the ticket is a comment or a new issue.

Feature Request
Can a feature be added to notify users of exactly where an issue is opened or commented?