thank you for your fast reply. I think i did not express the issue in a clear way: when a customer places an order, i, as a admin, receive a html notification with the new order info. This is how the header of the email looked:

the notification was from Ecwid but i had the reply to field with the customer`s email address.
This is how the header of the new email notification looks:

the notification is from Ecwid but i don`t have the reply field with the customer`s email address.
Now when i click reply, the to: field is with the ecwid email address.
Thank you