Directory and Resource Administrator 6.50
Startup time is excessively long for the MCS Onepoint Admin Server, to completely initialize and accept requests, if Exchange 5.5 support is enabled.
The cause of this issue is that the Exchange 5.5 mailbox count is in the same thread as the start up thread.
In Directory and Resource Administrator 6.6, the Exchange 5.5 mailbox count will be carried out in a separate thread from the start up thread. Therefore, the start up will be able to continue and the MCS Onepoint Admin Server will be able to initialize and take requests before the mailbox count is complete. Please upgrade to Directory and Resource Administrator 6.6.