After we upgraded to Freshdesk from free to the next level up we wanted to avail of the Custom email. We had set it up using IMAP for incoming and SMTP settings for outgoing. We tested it out from a test user and sent in a test support request. Back in Freshdesk portal we would receive two ticket submissions.

After checking my settings decided to undo the incoming settings and just leave the outgoing email settings. After this was done, tested it again with our test user and the duplicate emails stopped.