Each account comes with a personalized e-mail address. If your account is mycompany.estreamdesk.com then your e-mail will be email@example.com. All e-mails sent to your eStreamDesk e-mail address will be automatically converted to tickets.
You can set up a forwarding from your support e-mail address to your eStreamDesk e-mail address. If you use Google Apps or GMail then you can do it easily by using their "filters" functionality.
Forwarding mail in GMail
Forwarding mail in Exchange