Question about Outlook Express

I am hoping somebody can help me with this.  Last year, I realized spam was sent from my account when I saw a bunch of undeliverable emails in my inbox. I quickly changed my password to an even more ridiculously hard one with letters and more numbers, added the two step verification, and deleted many email contacts and many of my sent emails. A few weeks ago, I noticed spam was being sent from my account again when I happened to come across a message in my junk mail folder sent from my account and copied to me. I saw that this email was sent to contacts that are no longer on my contact list! (I now have a brand new computer, which is less than a month old, and it is completely free of viruses and malware based on the daily scans scheduled on it.) I changed my password again to be on the safe side, but noticed another spam email (this time in my inbox) just the other day. I have not received any undeliverable messages in my inbox in either of the last two instances. There is also nothing in my sent mail or deleted folders that I do not recognize and all of my security info isaccurate. Is somebody side stepping the two step verification or is this spoofing? Is there anything that I can do? Will closing the account help?

I have tried unsuccessfully to get help from MS Technical Support. After weeks of waiting and sending follow up messages, I finally received a response. They sent links onchanging my password and how to manage my junk mail folder. No questions were answered. I foolishly thought calling would be better. What a disaster. I had an incredibly frustrating hour long conversation with somebody who had a lot of difficulty understanding me. He did ask lots of questions about the US as he mentioned that he was in the Philippines and wanted to visit the states. This guy was the manager! Any insight from anybody would be awesome! Thanks.