Unable to see any Emails from Outlook .com. I have removed and reinstated the account after backing it up. The folders synchronise, but the emails do not appear. An email sent from Em client appears in sent and can be moved to inbox but no other emails appear, Send and receive gives synchronising but no messages can be seen. Log on to Outlook.com shows emails in profusion! also giving this error as well 
I’m having exactly the same problem!
This is most likely related to the fact that Microsoft has changed the way to download e-mails.
I solved it by disabling my current hotmail account in eM Client and adding a new account (selecting ‘Mail - other’ and using IMAP for my hotmail account this time).
This worked for me!
Simply adding another new Outlook.com account will not work.
Must add the new account exactly as Hans stated- as the type: “Mail-other”. This allows auto discovery of the IMAP or POP settings used by the Outlook server. In my case, it still could not authenticate these on the first try & I had to click the “Fix it” button for both POP3 & SMTP settings. The POP did finally find the right port number & set, the SMTP did not. I tried the SMTP again & still no. So I clicked the “ignore” button & let it finish setting up the account. I was then able to enter the SMTP port manually. (the numbers are listed on your outlook.com account under “Options”- Accounts- POP & IMAP) I am now receiving emails thru eM Client from my outlook.com account for the first time in 2 weeks! No thanks to Microshaft, but BIG THANKS to eM support!
Hello,
You might experience problems with your hotmail/outlook/live accounts if you have them setup using AirSync.
AirSync is a mail protocol that has been discontinued by Microsoft. All hotmail, live and outlook.com adresses are being migrated to Exchange protocol.
You will need to remove your account from eM Client and then either set ip up as Exchange or IMAP (if your particular account hasn’t been migrated yet).
eM Client version 7’s Automatic setup is set to IMAP at this time, but you can also do so manually.
To set up your account manually go to Tools>Accounts > New Account and instead of Automatic setup choose Mail>Exchange or Mail>Other.
For IMAP settings your incoming server is imap-mail.outlook.com and outgoing is smtp-mail.outlook.com.
Regards,
Olivia