We rencently upgraded our ould Exchange 2003 environment to a new HA 2010SP1 environment. A lot of usefull things were added, but a long known limitation just seems to remain intact: one of our users made a few personal Distribution Lists with personal contacts in, and after adding one more and restarting Outlook, Outlook 2010 and Outlook Web App both give 'insufficient memory' error messages when you try to access this DL. This was a know problem in 2003, as the whole personal distribution list was contained in a 32 KByte (or 15 KByte, depending on the source) datablock. When it grew larger, the DL was corrupt and could not be used anymore. I cannot believe the Microsoft engineers haven't fixed this issue 2 full versions later, in a system demanding 64bit servers for better memory management!! Is this problem still not fixed? Is there a solution to allow personal DL's to grow larger (at this time, they can only contain around 60-100 contacts, and the only solution is to combine multiple personal DL's which is not workable)...