Hi!I bought a UCCcert from Comodo and thought that all my problem with none trusted certificate would fly away.But no, I have to install the root certificate from Comodo on all my XPs and Vista to validate the UCC cert.If i dont do this Outlook anywhere would not connect, OWA is working but we get a warning about the certificate that it is not trusted.The question is: have i done something wrong or do I have to install the root certiface on all clients.IF this is the solution I cant see why anyone should use the certificate instead of two separate certificates.RegardsPeter S

Hi, Before going on, I would like to confirm whether the certificate that you purchased from Comodo could provide multiple names in order to ensure the connection is valid comes from various client. Such as OWA, Outlook Anywhere. Please understand that the communication between the Exchange and Client is over SSL channel. That needs certificate has to be trusted by the client. Thus, for the new certificate, when we first connecting the Exchange by using Outlook Anywhere, we will be asked for installing the certificate. In other words, the certificate has to be installed on the client. After that, please also ensure the URL that the client is trying to communicate must match the name of the certificate. You can view the instruction about this knowledge. http://msexchangeteam.com/archive/2007/04/30/438249.aspx Thanks Allen