MailShadow is a disaster recovery and/or mailbox migration platform specifically protecting Microsoft Exchange Servers. It enables mailboxes from a primary site to be transparently and asynchronously replicated to a remote site over a WAN link; with failover features enabling clients to switch over and begin working from the server on the recovery site if the primary site should fail. Queuing features then allow the process to be somewhat reversed for failback processing; i.e., transactions are queued from the recovery server back to the primary server until the primary server is fixed such that it can resume its duties.

The MailShadow architecture is such that no additional software need be loaded on either the primary or recovery Exchange servers. Instead, the product leverages the MAPI protocol and replicates the actual transactions across the WAN link for processing to "ShadowMailboxes" located on the recovery server itself. The vendor notes that these WAN communications are both accelerated--via compression, packaging, and buffering--and examined for integrity before transmission; i.e, the product waits until each transaction is complete and fully formed before sending it in an attempt to prevent the replication of corrupt data to the recovery server. When initially provisioned, the software automatically populates/initiates the ShadowMailBoxes from the contents of the original mail boxes; and then continues to keep the two mailboxes in synch as new transactions are received.

The actual transactions and WAN communications are performed by separate Windows 2003 Server machines; one at the primary server's site and one at the remote server's site. The transactions from multiple local Exchange Servers can be gathered at the primary site and replicated to a single remote recovery server, if desired; and mixed Exchange Server environments (2000/2003/2007) are also supported. Bi-directional transaction replication support enables two servers connected by WAN to serve as recovery servers for one another.

Licensing of the product is via the number of protected mailboxes, with administrators having the ability to specify only selected mailboxes for replication and the ability to add new mailboxes for replication as need and budget allow. Management of the product is via a centralized MMC management console in which both MailShadow Servers--local and remote--can be managed from the same console.

In addition to the product's ability to serve as a disaster recovery platform, MailShadow can also be used as a migration platform; by provisioning ShadowMailboxes on a later version Exchange Server (i.e., the primary server would be, for example, an Exchange 2003 server, while the recovery server is a Exchange 2007 server). Since the platform is transaction based, the two servers needn't be deployed on identical hardware. A "Permanent Failover" feature then enables the switchover to the new server when it has been verified as ready for business.

New features in the latest MailShadow release include performance enhancements enabling the product to scale up to a potential 20,000 protected mailboxes per pair of MailShadow servers (depending on E-mail load); support for automated provisioning and de-provisioning of all members of selected Active Directory (AD) groups or by Exchange storage groups; the ability to provision ShadowMailboxes on multiple recovery servers; and the ability to schedule the initial mailbox synchronization for a later time (nights or weekends, for example).

MailShadow is available now. List pricing is $50 per mailbox with $10 for annual maintenance and software assurance fee.

Contact Cemaphore Systems for further information.

product submission by EITPlanet Staff

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