I've recently upgraded to Microsoft 10 - felt I had to - and can no longer send emails from Outlook. It keeps saying that I have to check that I have the correct account settings. I've not changed anything else. Strangely, I can receive emails. Problematically, as I have not changed anything, I have no idea what to now alter to allow this to be resolved. Help !

I have what sounds like an identical problem.  I have a Surface Pro 3 that was running Windows 8.1 with Office 365. I have several different email accounts that it was checking through Outlook, and it has worked fine for several months.  Then yesterday I upgraded to Win 10.  Now although I can still receive emails, no matter which account I attempt to send from, they just sit in the outbox.  I went into the account settings and tested each account.  They were all able to send a test email fine, which I subsequently received.  Yet the emails I attempted to send before the test are still there in the outbox, and I still cannot send new ones.

Hey, I kept searching other forums, and eventually found a solution that worked for me. Though I'd pass it along. First, turn off all running apps, especially Outlook.  Then look at "All Apps."  Under Windows/System, find the Command Prompt. Right click on it and select "Run as Administrator."  At the command prompt, type:   SFC /SCANNOW      (make sure to include the space between 'C' and '/')  Let it run to completion.  When I did this, it fixed some corrupted files, and when I fired Outlook back up, it started working

• Proposed as answer by Stellerex Saturday, August 15, 2015 7:58 PM

thank you! it's not just me then. it seems to be something in Windows10. checking forums for a solution. As advice, I can log into my main webmail hosting solution and send emails from there and then directly receive responses in my outlook email box.

thank you, Stellerex. this seems to have worked. A big thumbs down to Microsoft for allowing this problem to be embedded in MS10 and not directly offering a solution.

To recover from the issue, you must run the Microsoft Windows Resource Checker tool, also know as System File Checker or sfc. This tool scans and verifies the integrity of all protected system files and replaces incorrect versions with correct versions.

1. Right click on the Start button of Windows and choose: Command Prompt (Admin).
   • If you dont see this, instead choose: Windows PowerShell (Admin)
2. Behind the prompt type: sfc /scannow
   (note the space in the command)
3. Wait until the process completes. This usually doesnt take longer than 20 minutes with a regular hard disk and takes much shorter when you have a fast SSD drive.
4. Restart your computer.