The emails from Freshdesk are sent through Sendgrid, which is our email service provider. If you are willing to use your own mail servers instead of Sendgrid to send and receive emails, you could use the custom mail servers feature of Freshdesk. 

You could set this up by adding the IMAP and SMTP details of your mail server, to your Freshdesk Account, under Admin > Channels > Email > Edit(corresponding to your email address)-->Use your own mail server.

If you have subscribed to the current plans, this feature can be accessed through the Growth plan. Alternatively, if you have subscribed to previous plans of Freshdesk, the feature is available through the Blossom plan.