If you have multiple email addresses to which your customers write to contact you, all these email addresses could be added to your Freshdesk Account. Thereby, emails coming to all these email addresses would get converted to tickets in your Freshdesk.
You could add a support email address by clicking on the New Support Email option under Admin > Channels > Email.
The functionality to add multiple support email addresses is available through the Growth plan if you have subscribed to the current Freshdesk plans. Alternatively, if you have subscribed to previous plans of Freshdesk, the feature is available through the Blossom plan.