E-mail services represent an essential part of the IT landscape of enterprises. Besides in-house hosting, every company can make use of offers from specialized application service providers (ASPs). Former research has shown a lack of transparency in the market for Web-based services. This paper summarizes the results of a study on professional web-based e-mail services catering to the German-speaking market. This research mainly addresses following questions: What are the similarities and differences between the various services in the market? To which extent do the offered services meet a corporation's requirements? What kind of methodology can be used to analyze and to compare web-based services? And, with that in mind, do web-based e-mail-services represent a serious alternative to in-house hosting of e-mail-services? To answer these questions we compared information of selected service providers on the basis of a multi-scenario utility analysis.