I have recently upgraded from Windows 8 to 8.1. After a successful upgrade I configured the Windows 8 Mail app to also sync with Exchange (2010 in house server). On my Windows Phone (Nokia Lumia 800) I have the same account configured.
This resulted in the problem that the Mail App and the phone do not want to send any emails that have been created by reply or forward.
The phone gives the following error:
"We weren't able to send this message, so we've put it in your Drafts folder. Before you try sending it again, you can check to see if the address is correct and that no attachments are too large."
The Mail App give the following error:
"There's a problem with sending messages from xxxx.xxx@xxxx.com at the moment. Check with your provider for more info."
If I create a new email there is no problem.
I have searched all over the internet for a solution to this problem, but could not find somebody with exactly the same problem.