[otrs] Ticket from Email automatically assigned

Hello all, We would like to receive the tickets from users more via email, less via web interface. The problem is, that when mail comes, customer is not automatically assigned according email address, unfortunately it must be done manually zoom>customer>search customer>take this user>update. I find this way as very time consuming, I would like to have some smarter solution. Please help me - is there any possibility to have it automatic? Thanks in advance Marek Drnak