Hi all,
Thanks for all the help. I got the incoming mail working fine now. It's just the outgoing mail that is still not working.
I've compared what I have on my work iphone with what I have on my personal one and I cannot see a difference. Sigh.
Oh well. I'm sure things will sort themselves out at some point. 😁
Posting this in the event it helps someone in the future.
I tried all the above steps and was still unable to log in.
The fix in the end for me, was changing my password. The password I was using originally had a '£' symbol in it. Once I changed password and removed the '£' it logged me in straight away.