Microsoft is looking for four customers to help it promote the mobile e-mail and unified messaging features in the next version of Exchange Server, according to a posting on the company's Exchange team blog.Microsoft aims to recruit customers "with an interest in unified messaging or mobility" to participate in an advertising campaign for Exchange 12, according to a posting Friday on the You Had Me at EHLO blog attributed to Michael Liu, a senior product manager for Exchange.According to the blog entry, the advertising campaign would go live in the fall season in the U.S., which is from late September until late December.Liu did not immediately reply to a request for more information on Friday.Exchange 12 will feature new technology for pushing e-mail directly out to mobile devices, Microsoft has said. It also will have unified messaging capability built directly into the product, which will enable users to access not only e-mails, but also voice mail and fax messages through Exchange. Previously, this kind of functionality was only available through third-party products.Microsoft will provide customers chosen for the campaign with resources to deploy either unified messaging to 100 Exchange 12 mailboxes, or 20 mobile phones to deploy on 100 Exchange 12 mailboxes, according to Liu's posting. The company also will provide a dedicated Microsoft engineer or partner to help the customers deploy Exchange 12 and two 64-bit servers to run the product.Exchange 12 will be the first version of Microsoft's e-mail and messaging server to be available only on 64-bit hardware, a change that has some customers concerned because it may mean they will have to purchase new hardware.For customers participating in the unified messaging part of the campaign, Microsoft also will provide a dedicated consultant to integrate Exchange into a customer's phone system.If chosen, customers must participate in Microsoft's global advertising campaign for Exchange 12, provide a project manager, deploy 100 mailboxes on beta 2 of Exchange 12, work with Microsoft and other consultants to assist with technical implementation and provide public relations or marketing support to coordinate advertising activity, according to the posting.To be considered for participation in the campaign, customers can e-mail Liu at email@example.com with their company name, contact e-mail address, number of employees, number of Exchange mailboxes deployed and primary messaging system.Exchange 12 is expected to be available in late 2006 or early 2007, according to Microsoft. Beta 1 of the server is currently available to about 200,000 beta testers, including Microsoft Developer Network and TechNet program subscribers. The company expects to release Beta 2 of Exchange 12 mid-year, a Microsoft spokeswoman said Friday.