[otrs] Auto Response tags not working?

Dear List, I am not sure %100 It was working previously, when a first time customer user (not recorded as customer user in the otrs system) sends a mail to the system, auto response can not resolve user's name from the email. I tried below three tags in the template but it is still put system default email address or display name in to the mail. Examples: Thank you Thank you Thank you All these variables returns something like below, Thank you helpdesk@otrs.com or Thank you Helpdesk instead of Thank you Yilmaz Bilgili --- I am using OTRS 5s on Debian up to date stable system. How can I resolve this? Thanks in advance. Best regards, Yilmaz