Server 101: Access multiple Exchange servers with Outlook

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Server 101: Access multiple Exchange servers with Outlook

Lugging the same laptop from one job to another? There is a way to access multiple Exchange mail servers with Microsoft Outlook.

A decade ago, if someone told you they had more than one job you'd assume they were hard up - working day, night and weekends to make ends meet.

Nowadays, though, all kinds of people wear several hats, maybe doing Monday and Tuesday for company A, at-home consultancy on Wednesday, and the rest of the week working for company B. Your emails tell me this kind of arrangement is fairly common among the readers of this column.

Chances are you lug the same tooled-up laptop to all these jobs, have access to both company A and B's mail servers, and that these mail servers are both running Exchange Server. And that's where the problems begin, because Microsoft Outlook appears - at a casual glance - to be only able to talk to a single Exchange Server.

You'll need to choose the proper Exchange connector for one company, but fall back on POP3 or IMAP to access the other - better than nothing, but it doesn't give access to shared calendars, contacts and other niceties such as setting your Out Of Office message.

I'm going to tell you about a solution, but first I want to clear up a common misconception.

The desktop version of Outlook can be configured to access multiple servers, just not simultaneously. The actual limitation is that your Outlook mail connection settings are stored in a "mail profile", and it's that profile which has the single Exchange Server limit.

There's no reason why you can't keep two profiles, one for when you're working at company A and another for company B - it will kind of work, but you can only have one open at a time, which means that if an important email about company B arrives on a Monday then you won't see it until you next switch profiles, probably on Thursday...

"Aha," I hear you say, "why not simply run two instances of Outlook, each using a different profile." That would be almost, but not quite, perfect.

Trouble is, it doesn't work. No matter what you do, even creating two differently-named copies of the exe file, it's almost impossible to persuade a second copy of Outlook to launch.

Even having a different user profile (as opposed to Outlook profile) and trying to run the second instance via RunAs won't work - you still end up with a single copy of outlook.exe running, so there's obviously something sneaky going on under the hood.

Notice how I said "almost" impossible there? Fortunately, there are some very clever people out there, and a couple of them decided to attack this problem head on.

First, take a look at this blog of a "reverse engineer" called Jason Geffner, who managed to find out exactly how Outlook has been deliberately designed (some might say "hobbled") so that only a single instance will run.

Next, head over to the download page on security expert Timothy Mullen's site, where part way down the page you'll find something called ExtraOutlook. Download this, unpack the zip file and place extraoutlook.exe somewhere in one of the folders in your path.

Then configure your copy of Outlook to ask for a profile when starting up (the settings for this are in the Mail part of Control Panel), and fire up a copy of Outlook as normal, connecting to your first profile. Then open a command prompt and type:

ExtraOutlook c:\program files\microsoft office\office12\outlook.exe

You'll need to change office12 to office11 if you're still running Outlook 2003. And that's it, you should see a second copy of Outlook open, and you'll be able to select your second profile from it. You'll probably want to put the ExtraOutlook command line into a batch file to save typing it out each time.

Finally, you have proper access to both enterprise A and B's mail servers, and sure it's a bit of a hack but, hey, it works. Of course, what I really want now is the same multiserver flexibility on my mobile devices: both the Outlook Mobile in WM6 and the enterprise versions on BlackBerry only work against a single Exchange Server.

Wouldn't it be great if they, too, supported more than one corporate email system? Perhaps these should be the next jobs for Jason and Timothy!

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Two copies of Outlook 2003, both accessing different Exchange Servers
Copyright © Alphr, Dennis Publishing

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