Thanks for this...those of us that continued contributing to this thread have provided ample evidence to show it's not an iOS issue.
BT need to investigate further. Can't simply wash their hands of it and blame the issue on a third party. Poor.
I mentioned in message 13 I agree that it is not an iOS or device issue however as BT are contracted to supply you with an email service and as your email service is working via webmail, the only format for receiving/reading email that BT support, as far as BT are concerned they have fulfilled their contract.
As has been pointed out, while BT supply you the information/settings and indeed the servers so that you can use email clients on your devices, they do not offer support for for such use and as you have found it is very difficult if not impossible to get any assistance from BT if your email is working via webmail.
Did you try my suggestion of trying another email app instead of the stock Apple one or Outlook?
Actually Outlook seems to work ok for me- it just seems to be Mail that is the problem. I have looked on the app store for others but the thing is Mail just works across different apps on all my devices really well including with iCal etc so it is annoying if I have to use a different one. Outlook is not a nice interface in comparison.
If Outlook and if other email apps are working and the problem is only apparent when using Mail it would tend to point to a problem with either Mail or its settings. If it was a BT server problem it is doubtful that any email app would work for you.
When setting up an email client it is best to do it manually, entering all the settings correctly rather than using the "wizard".
In case you are unaware how to set up the email account manually:-
When you set up Mail on iphones in order to get to the manual settings you need to set up your email account with the wrong email address or password. This will cause a failure of the account authenticating and it will open up the manual settings.
You can then select to set up as an IMAP or POP3 account and you can enter all the correct settings, including the correct email address and password, and tick the correct boxes as per the BT settings in this link.
EDIT: For the purposes of testing you can set up Mail as well as Outlook or any other email app on the same iphone at the same time so you do not need to delete Outlook in order to try another email app.
Thanks but seeing as all of our email accounts have been working perfectly for months / years and are now only working intermittently over the past few days, I doubt very much it's our fault for entering the incorrect settings.
I've been using an iphone for several years with no issues. I've deleted the account and re-added it over the past few days which sometimes makes it work for a little while then it stops again.
My other email accounts are all fine.
Fair enough but how would you explain if Outlook and if other email apps are working and the problem is only apparent when using Mail that it is a BT problem. If it was problem with your email account profile at the BT end it would in my opinion be a problem using all email clients not just Mail.
Sorry but I am at a loss can offer nothing further.
Well, I haven't tested out all the apps yet and perhaps if I had Outlook for longer then it would also have problems - even now Mail is working at some times and not others.
It just seems that as so many people are having the same problem and only with BT mail it must be something to do with the combination of the two. I haven't seen anyone on Apple forums saying that Mail is having general problems.