Mountaineye

Hi, Could anyone guide me through the last bit of setting up an Iphone to send through Cumbria schools email? I can receive ok so have some parts in place. It rejects username/password but in themsleves they are correct as they work through Outlook. We're not using Exchange. I've searched the forums and don't find any reference that is not exchange related. Using T-Mobile/Orange. Using mail.cumbriagfl.org.uk and outgoing port 25. Many thanks.