Mail In Confirmation Emails (Sender Name)

When a offer is submitted - When the customer receives the mail-in confirmation email they are seeing an unexpected sender name “Sell Thebuybackplatform Noreply”

Our email address we use is “NoReply@thebuybackplatform.com” and the reply-to address is HappyToHelp@thebuybackplatform.com however the customers seeing “noreply@sell.thebuybackplatform.com” with the sender name “Sell Thebuybackplatform Noreply”