You don't have any sending reputation. That can cause an issue:
Lookup for 37.205.10.44 - SenderScore.org
This is better than a bad reputation, but not as good as having an established reputation as a good email sender.
You are not listed on any RBL's. Your SPF record looks good.
Check your outgoing mail logs? What do they say about the delivery attempt to to the live.com email address?
Sometimes Microsoft quietly eats suspected spam. Also send a test to a Gmail account. Does it at least make it to the spam folder?
Keep sending email to those that want to receive it, won't mark it as spam, and will help with marking as "not junk" and the situation should improve.
If you can post the delivery log to live.com that should help. With the delivery log I can help you open a ticket with Microsoft if needed.