Our external mail provider has a download plugin that works with Outlook that will allow you to see any emails that have been sent/received on your account. You can download it here after you install this, you can go to the Mimecast tab and enter your domain credentials (email address and computer login password)
Mimecast also has an online Quick Start Guide to help you walk through the basic functionality of the plugin, you can view it here
--this is sort of out of date as of 12-8-2015 at 5:15 am --Our mail server is down at the moment, but don't worry, you can access your sent and received emails by clicking here and logging in to our online mail portal using your email address and the password you use to log into your computer.
There are also mobile apps available for download for both Apple iOS and Android
Download for Apple iOS here
Download for Android here