Although I would miss my “moose” account… on the “zoo” cluster at our local uni…I’ve always recommended most small organizations (under 100 FTE) not maintain their own eMail server, (usually Exchange), unless they were using it as a platform for business applications. Usually the same internet service provider which hosts your web site will also host POP or IMAP eMail accounts for little or nothing, and they’ll include spam filtering. They will provide access to a “web mail” version of your eMail when traveling. All this with no advertising, or intrusions, and usually for free.
Inside Higher Ed has an article about the outsourcing of eMail servers by higher education institutions, usually to Microsoft or Google, with versions of Hotmail and Gmail offered specifically for higher ed.