Disable Email Submissions for Specific Users

[Kurtis]

We would like to alter our email submissions to meet the following criteria:

• Prevent users from submitting tickets via email.
• Email comments/replies need to remain functional.
• Specific emails must be able to submit email tickets since they are automated (Voicemails emailed to Service Desk).
• We would like an autoreply so users will always be reminded that the email doesn't make a ticket. Right now this is managed via the Exchange Online mailbox.
• Maintain the connected Exchange Online mailbox.

I found the post below but this doesn't seem to solve my issue. 

Solved: Disable email requests but keep email comments (atlassian.com)

[Brant Schroeder · Accepted solution]

@Kurtis in the post that you reference there is not a way to disable emails that are sent to the service desk.  As Atlassian support stated you can add an auto response letting the user know that they have to submit issue through the portal and you can close the issue.   This is really the only way to do this at this time.  

[Kurtis]

I ended up setting up rules in Exchange that sent an autoreply if the email subject doesn't contain ticket key information. This allows for email replies to still work but prevents ticket submissions via email.