Fixing internal email function with WHM on a dedicated server

Hi There, My current WHM server is svr1.domain.com which runs on a CentOS with WHM. I have configured its email service to pass through a relay while discarding any email generating using the server name (e.g.: an account named acc1 using cPanel has a wordpress which has a contact form. The contact form uses hosting's internal mail function upon some anon user submitting a query. Then the mail generates on cPanel as acc1@svr1.domain.com). Which means any mail generates as account_name@svr1.domain.com will be discarded. Now, the question is; is there another way to over-come this issue.