I am receiving the below error from my Hotmail account:
[Exchange Web Services] Sending email failed due to the following error: The user account which was used to submit this request does not have the right to send mail on behalf of the specified sending account., Cannot submit message.
This usually happens when the from address of your message is different to the address you are using to login to the server. Most email providers don’t allow that because it is something spammers use.
Go to Menu > Accounts and click on the General tab for this account.
Set the Email field to the same address you have in the Authentication login name field.
Click on Save & Close when done.