Hi Max,
I forwarded your answer onto IT staff and this was their response. DoE Guest is a reference to Department of Education guest accounts:
"Yup, epicgames.com and sub domains are all allowed in our proxies. Evidence by the fact that on DoE Guest, the launcher works and lets you login / download the content happily.
DoE Guest is subject to the same proxy filtering as anything joined to the education domain, the only difference being that web traffic goes directly to the default gateway instead of the machine requiring proxy details to be entered."