The standard SPF records that we publish for most mail domains under the cam.ac.uk domain say that mail is permitted from the entire CUDN IP address space and Microsoft Office 365 Exchange Online.
Other IP addresses are marked "neutral" (i.e. neither positively permitted nor explicitly forbidden).
Specifically, our standard SPF record is:
cam.ac.uk. TXT "v=spf1 include:mx.cam.ac.uk include:spf.protection.outlook.com ?all"
Several mail domains have special-case SPF records to allow for different off-site mail service providers.
Please let firstname.lastname@example.org know if you need any changes to your mail domain's SPF record, or if you want an opt-out.
The SPF record published at mx.cam.ac.uk covers the whole CUDN. This name is also used for incoming mail via the central mail relay. We re-used this name for SPF because it is conveniently short and mail-related.
Despite the name, the SPF record covers the entire CUDN and is not specific to the central mail relays.
Last updated: 16 February 2017