You can connect to Microsoft Office 365 using Mozilla Thunderbird 8.0 using either Mac OS X or Windows. Thunderbird provides both POP3 and IMAP4 capability. However, you won't get all the functionality available with full featured E-mail clients, such as Microsoft Outlook.
Help with Mozilla Thunderbird 8.0 is available at the ITS Help Desk and the Open Access Labs.
Please note, all of the links below point to instructions on Microsoft's web site. As updates are made to Office 365, these instructions will also be modified to show the most up to date information. The same is true if Thunderbird is upgraded. If you experience problems connecting your system to Office 365 using Thunderbird, you may want to check this site to see if changes are required in the setup for your computer.