I have not seen this expression myself - if you wanted someone to reply to your email and felt that you needed to say so in the email, you would write "please reply" or " I would appreciate a reply to this email".
I would guess that the person who used this expression may not be familiar with English and is trying to say "reply to" but using the wrong word.
Perhaps others on Italki have seen this expression but I haven't and would not recommend you use it.