We have a relatively unusual issue in that we have apparentlyhit the limit of Address Lists / Global Address Lists that Exchange 2007 can support. We have implemented a customised Exchange 2007 system to host e-mail for 600 Schools. Each School requires it's own Staff and Student Global Address Lists. Also there is a potential need for Offline Address Books for Staff, thus requiring separate Address Lists forStaff within each School. This would equate to about 1,800 Address Lists and Global Address Lists in totalI have seen an article stating that the theoretical limit for Address Lists and Global Address Lists is about 1,300. We had created about 1,270 when it refused to create any more stating that it had reach the administrative limit.Does anybody know whether this is a fixed limit and whether there is any workaround?Also can anybody suggest an alternative way of providing a segrated mail system (but with the flexibility to allow users to be visible or hidden from their Address Lists). AD is broken down into individual School OU's and Staff and Students OU's within that.

Did you see this post?http://social.technet.microsoft.com/Forums/en-US/exchangesvradmin/thread/146301ca-92eb-48de-830a-56cebc214af9Seems its a limitation of the miltivalued attribute - not Exchange itself. I would expect without a schema extension this number cannot change.

Mike,Many thanks for your response. Since raising this call I have found about a utility 'MakeGalLinked' that can extend the number of Address Lists that can be supported (see below). However, it needs to be run before installing Exchange 2007, so is too late for us. I have since been able to reduce the number of address lists required so hopefully won't have a problem with this limit again.http://technet.microsoft.com/en-us/library/cc526566.aspx

good deal. thanks for the link