SPF defines which servers may send email for a domain. Forwarding can cause a problem: the forwarding server may not be authorised by the original sender’s SPF record.

This can lead to a rejection such as 550 rejecting for sender policy framework.

EDIS uses Sender Rewriting Scheme (SRS) when forwarding email. SRS rewrites the technical envelope sender so that forwarding can pass an SPF check.

SRS does not guarantee delivery under every recipient policy. If a forwarded message is rejected, send the complete error message and details of the forwarding route to EDIS support.