Any suggestions: mail will not load from my exchange server

Good evening all,
I wonder if you could suggest anything for this issue? Since this morning, 4.30 AM UK time, I have not had any e-mails load from my exchange server. Every time I open 'exchange' I get the message 'server error, please contact your administrator'. I have double-checked by open the same e-mail source which is from my higher eduction instution where I work and it is fine, e-mails load ok and I can read them all using Jaws. I have also sent an e-mail from my lap top (when I have my higher education account that I am talking about and the one that will not load on my iPhone) from a different e-mail account that I own (this is a sky account) and the e-mail appears in my sky folder in my 'mail' account on my iPhone.
I have tried completely turning off my iPhone and turning it on again but the problem is still there. Can anyone help?
I have an iPhone 6 running IOS 9.0.2.

Thank you,

Steve.