The default MTA on a CPanel server (Exim) has supported both the Sender Policy Framework (SPF) and the Sender Rewriting Scheme (SRS) for quite some time. Unfortunately, whilst CPanel provides configuration options allowing you to enable and configure SPF, the same cannot be said for SRS.
This can cause a major headache if you have set-up mail forwarders on your system. This documentation details how to go about configuring SRS.