I am assisting a new user with his outlook.com account

We are following the instructions:

1. Sign in to outlook.com

2. Click on (v) beside New and select Event.

3. On details page, fill out the particulars.

4. Click on Attendees.

5. Enter the email address of recipients into the Invite people box.

6. Click Send invite.

Open the event and go back to the attendees. It shows "Hasn't responded - 1" but the email has never been sent to the person(s) we have invited. Checking the sent items under mail does not show the email being sent either. All new events have the same behavior.

I have checked my Outlook.com account and found that the invite is sent and the invitation shows in the sent items. This seems to be an account issue.

Another (I think) unrelated issue, new contacts added to an Android phone running the Outlook.com app installed do not sync back to Outlook.com.