Hi All: The current scenario is as mentioned below; # We have Linux mailing Servers at 9 locations with 1 node running at each location and mailboxes on each node.(Total 7000 mailboxes) # The Server at the HO serves as SMTP gateway as well as MX Server. # The other nodes don't have direct Internet Access to send out Emails, however they are connected to the HO thru IP links/VPN. # The HO Server is also the master LDAP Server. The above solution needs to be migrated to an Exchange Based Solution. Since we are in a process of migration we plan it to move it Exchange 2007 instead of Exchange 2003 to avoid future migration again. We need to provide a Cost Effective + High Availability Solution to the management. This is what we have planned so far as far as the architecture is concerned; # At HO: Domain Controller (1 No) + Additional Domain Controller (1 No) Client Access Server + Hub Transport Server (2 No's) Mail Box Server (2) connected to a SAN Box. # At one branch office (where we have maximum no of users) Additional Domain Controller Client Access Server + Hub Transport Server (1 No) Mail Box Server (1 No) Rest all the Branch Offices will connect to the HO Directly for their mails. Kindly let me know if we are missing out on any point. Thanks & Regards Mitul Z -- **************** CAUTION - Disclaimer ***************** This e-mail contains PRIVILEGED AND CONFIDENTIAL INFORMATION intended solely for the use of the addressee(s). If you are not the intended recipient, please notify the sender by e-mail and delete the original message. Further, you are not to copy, disclose, or distribute this e-mail or its contents to any other person and any such actions are unlawful. This e-mail may contain viruses. NetMagic Solutions Pvt. Ltd. has taken every reasonable precaution to minimize this risk, but is not liable for any damage you may sustain as a result of any virus in this e-mail. You should carry out your own virus checks before opening the e-mail or attachment. NetMagic Solutions Pvt. Ltd. reserves the right to monitor and review the content of all messages sent to or from this e-mail address. Messages sent to or from this e-mail address may be stored on the NetMagic Solutions Pvt. Ltd.'s e-mail system. ***************** End of Disclaimer *******************