Mediawiki Emails being marked as Spam Issue

Hello all - I have a Mediawiki based website ([login to view URL]), and the issue is, when an email is sent from the website, it is marked as spam by yahoo, hotmail, and other popular email services. Feel free to test this out by creating an account on the site, setting up a profile, and then changing the email and you will receive an automatically generated email response confirmation that will be marked as spam. The hosting company is [login to view URL] - and I am certain the issue is not because of the hosting company, or because of the text in the email, because my other mediawiki website here: [login to view URL] is able to send these same emails without a problem. I am willing to pay someone's hourly rate for as many hours as needed to resolve this issue! Find attaches an example email with headers that was sent to my hotmail account. -Adam