Yes and No. If you are sending email from our shared hosting servers (such as from a website contact form) your email will be filtered through our Ironport systems. This helps keep our servers from gaining a poor reputation.
If you are using our Skybox and Exchange services, we don't actually filter email, but the amount of email being sent from a box is monitored, so that should a mailbox become compromised, the box/domain can be shut down and you notified of the activity. For information on our Mail Acceptable Use Policy, you can go here: http://www.liveoakhosting.com/resources/live-oak-mail-acceptable-use-policy-aup/