I have had my Lumia 635 for more than 12 months with no problems, bu a few days ago it started giving error 80048811 when retrieving emails ( something about not being able to retrieve partial emails).
I have searched everywhere I can think of but I have not found the solution (some suggestions say change port settings, but I cannot see any way to do that on the phone).
My laptop and desktop are working perfectly so what is the solution?
I know I can change to a different email provider, but I am reluctant to do that.

I wonder if is worth deleting the account from your phone and setting it up again afresh? Don't pull the trigger on that just yet as someone who knows better than me might think it is a bad idea.

(for what it is worth I use outlook.com on my Lumia 820 and on my laptop as my web email client which I have set up to scrape emails from my BT Mail box amongst others)

Not been able to solve this, so what I have done is to forward emails from BT Mail to my Outlook email address, everything works fine now

I have a 635 as a secondary phone and the only thing I can see that may be causing you problems is that sync has accidently been turned off.

To check, tap the email address as if to read your emails from that address then down at the bottom of the screen, right-hand side next to the search icon is three dots, tap this then select settings and make sure “Conversation” is turned on and that there is a tick in the “In conversations, show replies and email from all your synchronised folders”.

You’ve probably already done this but just in case.