REVIEW: Cemaphore Systems' MailShadow allows for Microsoft Exchange Server or another e-mail system to be synchronized in real-time with an off-site, cloud-based alternative. This provides a real-time backup of critical e-mail, calendar and contact information, while giving users the ability to access the information from anywhere the Internet reaches. However, during tests, eWEEK Labs experienced management and performance problems.
The idea behind Cemaphore Systems' latest version of MailShadow is,
at first look, a promising one: allow for Microsoft Exchange Server or
another e-mail system to be synchronized in real-time with an off-site,
cloud-based alternative. By doing this, you have a real-time backup of
critical e-mail, calendar and contact information, while at the same
time giving users the ability to access the information from anywhere
the Internet reaches.
The MailShadow approach is, in a way, a lot like the synchronization
that happens between your Palm device or your BlackBerry and Exchange.
It can work in both directions so that any change made in one e-mail
system, such as Google's Gmail, is also reflected in the other, such as
Exchange. However, while the idea is a good one, the execution of the
idea leaves much to be desired.
During my tests of MailShadow, in which I synchronized an Exchange
mailbox with a mailbox hosted on a free Google mail account, I
experienced a series of problems, including multiple account lock-outs
by Google, the causes for which Cemaphore could not explain. What's
more, MailShadow lacks support for network connection throttling and
offers no information on synchronization progress, two feature gaps
that could leave companies that deploy MailShadow on multiple desktops
with an Internet connection that's saturated for an unknown amount of
This is not to suggest that MailShadow is without value. Its ability
to provide continuous, reasonably current copies of your e-mail,
calendar and contact information can be an important disaster recovery
solution for businesses that don't have another means available because
of technical or cost constraints. In addition, MailShadow provides a
promising way to migrate from one mail system to another without any
Cemaphore Systems' MailShadow Desktop Edition is priced at $49.95 per mailbox. For more information, see www.cemaphore.com.
For larger enterprises, there's a server version (not tested in this
review) that consolidates many of the activities that take place
individually on the Desktop version, and could make it easier for
administrators to overcome some of the product's limitations.
MailShadow in the Lab
While the earlier versions of MailShadow were focused on Exchange
and one of a couple of Internet based e-mail systems--namely, Gmail and
Exchange Online--the new version is meant to work between any two
e-mail systems. You can theoretically sync your POP3-based e-mail and
your Gmail account and not use Exchange at all. However, the thrust of
the MailShadow application is aimed at corporate users of Exchange with
the other end of the process in the cloud running on Gmail.
The good news is that once you get MailShadow running, it works. The
bad news is that, when teamed with Google's Gmail service, MailShadow
is subject to the vagaries of external forces which, understandably,
lie outside of Cemaphore's control. The prime example of these vagaries
were the recurring Gmail service lockouts I experienced while testing
The lockouts may have been the result of too many folder openings,
or perhaps too many sign-on and sign-off attempts, or perhaps too much
data sent at one time. The support staff at Cemaphore wasn't sure why
attempts to update the Google sites were sometimes unsuccessful
because, they say, Google doesn't make this information public. What's
more, Cemaphore wasn't able to tell me whether I'd experience the same
lockout problems with a paid Google mail account.
Part of the lockout problems I experienced may have been due to the
fact that, in the process of performing its synchronization duties,
MailShadow will use whatever bandwidth it has available. I tested
MailShadow on a Hewlett-Packard dual-Xeon workstation running Vista and
Outlook 2007, sitting behind a 20M-bps connection to the Internet. The
impact on the 20M-bps Internet connection was such that other
applications on other computers sharing the connection had difficulty
reaching the Internet quickly enough to avoid time-outs and delays. I
could have added some external means of throttling my test client's
available bandwidth, but I would like to see Cemaphore incorporate
basic throttling controls in the MailShadow product.
Exacerbating the problem with bandwidth usage is that MailShadow
provides no means of telling you how far along it is in its sync
process. If you're responsible for a large number of machines that all
need to be synced, you have no way to know whether to devote a day, a
weekend or a week to the process. And because it's never really clear
when synchronization is done, you never really know when your copy of
your e-mail is actually up-to-date.
Earlier versions of MailShadow ran within Outlook. The new version,
MailShadow Desktop Edition, is a background application that claims not
to need Outlook for it to function, but not all Exchange profiles are
configured to allow this. In my case, I had to start up Outlook and
leave the software running the entire time that MailShadow was
Once the product is installed, your only management task is to
choose which mail profile to synchronize, and which mail account should
be on the other end. MailShadow is meant to start up with your
computer, and then go about its synchronization continuously. I could
start and stop the process by clicking on an icon in the Windows System
Tray and choosing to start or stop.
Wayne Rash is a Senior Analyst for eWEEK Labs and runs the magazine's Washington Bureau. Prior to joining eWEEK as a Senior Writer on wireless technology, he was a Senior Contributing Editor and previously a Senior Analyst in the InfoWorld Test Center. He was also a reviewer for Federal Computer Week and Information Security Magazine. Previously, he ran the reviews and events departments at CMP's InternetWeek.
He is a retired naval officer, a former principal at American Management Systems and a long-time columnist for Byte Magazine. He is a regular contributor to Plane & Pilot Magazine and The Washington Post.