I have made some reservations for domestic air tickets on http://www.english.yoee.com

They have charged my credit card but I have not yet recieved any E-tickets by email.

When I emailed them about this they said that I don't need any printable E-ticket and that I only have to show my passport at the airport check in.

Is this true? Does anyone have similar experiences when making reservations through yoee.com?