There are a few steps that need to be checked for this issue:

  1. Go to Tickets tab > click on the view name at the top of the page > select the Spam folder > check if the ticket is present here. If so, restore the ticket > click on the Activities at the top right corner and check if there are any automations(Dispatch'r etc) that have worked on the ticket. If not, click on the contact's name displayed to the right of the ticket > check if the contact is deleted. Restore the contact and all future emails from the contact will come through as tickets. 
  2. If the issue is for all emails coming to your support email address, check if the forwarding rule has been set up as shown in the link. Only if the forwarding rule has been set, would emails from the mailbox get forwarded into Freshdesk as tickets. You can check if the forwarding address is working by sending an email directly to the forwarding address displayed under Admin > Email. 
  3. If the 'From' and 'To' addresses of the email is the same, it will not get created as a ticket in Freshdesk. The same applies if the 'Reply-to' and 'To' addresses are the same. 
  4. If you are in the Estate or Forest plan, please check if you have enabled Helpdesk Restriction (only emails from specific domains can be created as tickets). Move to Admin > Helpdesk and scroll down to check the same. If you have chosen 'Users from whitelisted domains', change it to 'Users from any domain' and save the changes.