Now we are able to deploy Exchange Server 2007 using a single certificate, but to do that we have some prerequisites, such as: add an SRV entry in the external DNS, update on top of Outlook 2007.
Read more at source: http://msexchangeteam.com/archive/2007/09/21/447067.aspx
Technorati : DNS SRV records, Outlook 2007
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