Original sender address not getting forwarded

Original sender address not getting forwarded

Hello;

      From our organization's webpage our customers can send in an Email request. This is routed through Outlook 365 to the Helpdesk mailbox, which in turn gets forwarded to the Zoho Desk support system to create a ticket. We used to be able reply via email from within the ticket, and it would have the original sender's email address. But for the past month or so it has onl had the Helpdesk emai address, not the senders. Any idea how I can get this changed back to the way it was before? Now I have to go back to the Helpdesk mailbox, track down the initial Email and reply to it to get the senders address. Then I have to copy my reply back to the ticket to track it - this is a huge waste of time.

Thanks