I asked them to unblock as much as needed doing last week, I guess something has been missed somewhere.
Thanks for all the advice
They've probably unblocked port 25 as you requested; they may not have assumed that you want to use their smarthost as well.
Just to update.
I now have email working.
i had the wrong domain in my email addresses!
My users were email@example.com when it should have been firstname.lastname@example.org.
Also our provider were blocking a few thing which they unblocked over the half term.