To make it harder for spammers and scammers to forge email claiming to originate from the ed.ac.uk domain, the University will shortly be changing the DMARC sub-domain policy (sp argument) to “reject”.
This change will tell any mail services that use DMARC and SPF tests when validating email, that any email that fails the SPF test for any *.ed.ac.uk, that it is recommended that the mail be rejected.
This, if we did nothing, could affect mail being sent as from @inf.ed.ac.uk addresses. However we have a DMARC record for inf.ed.ac.uk which currently sets our policy as “none”, which will take precedence over the ed.ac.uk’s sp=reject.
Users are unlikely to notice any change (other than hopefully a reduction in forged email claiming to come from a legacy domain like @dai.ed.ac.uk).
However if you are sending mail as coming From: an address that is not @ed.ac.uk or @inf.ed.ac.uk, then mail relays may start flagging your mail as suspicious, and marking it as spam.
Similarly if you are sending mail as From: @ed.ac.uk or @inf.ed.ac.uk but not using the Informatics or University relays as your outgoing SMTP server, then again other relays may see your mail as suspicious and flag it as spam.
Update 7/2/2022 – Currently this proposed change has been postponed, but will happen at some point in the future