Syncing Multiple Exchange Computers Solution

sansnil · 06/11/2008, 03:42 PM

I'm posting this in case someone else needs it sometime as it took me a while to find.

I have a personal home Exchange server account and a work Exchange server account. I wanted to be able to synch my home and work contacts and calendars (don't use work Tasks and just want personal email). I had a really difficult time trying to find a way to do this, and after looking at multiple third-party products still couldn't find a way.

But then I found some information about WM6 that indicated Microsoft had added a new cross pollination registry setting that was defaulted to prohibiting 2 Exchange server accounts from being sync'ed. I changed the registry setting and now it works just as I wish. My home Exchange account syncs wirelessly/push and I can BT or cradle dock my Treo 750 at work and all 3 get synced up together. Nice. Didn't even cost me a penny.

Here's the short of it:

Synchronizing a specific information type with two PCs at the same time is referred to by Microsoft as "non local cross pollination". With Windows Mobile 6, Microsoft introduced a new registry setting that enables or disables this feature. The key is a REG_DWORD key at the following location:

HKEY_CURRENT_USER\Software\Microsoft\ActiveSync\EnableNonLocalCrossPollination

The default value is "0" which disables the feature. Changing the value to "1" will allow you to select multiple computers to be synchronized.

Do a soft reset and configure ActiveSync on your device to use both computers for syncing and you're good to go.

The full article/instructions can be found at:

http://www.bitshift.ch/eng/support/kbase/000003.asp

Hope this helps someone else one day...great way to sync a calendar on multiple computers, etc.

holmes4 · 06/12/2008, 06:30 AM

I'd be happy to synchronize to the SAME server using two different PCs (my desktop and laptop). Supposedly I'll be able to do that with this edit - will have to try it.

fastlerner · 06/12/2008, 10:33 AM

Nice find sansil! I'll be checking this out when I get a chance.

One thing though... When you set up your sync relationship, is your Treo still set to sync those items over the air with exchange, or do you have to push it back to sync over the cable only?

fastlerner · 06/12/2008, 10:47 AM

Figured it out. Here's the full details for the many folks I know are interested.

HKEY_CURRENT_USER\Software\Microsoft\ActiveSync\EnableNonLocalCrossPollination

1) Establish sync relationships with the PCs in question
2) Change registry value listed above from "0" to "1" on the Mobile device
3) Reboot your mobile device
4) Open ActiveSync on the mobile device and go to Menu>Options
5) Under the "windows PC" section check calendar, contacts, tasks etc...

That's it! It doesn't change that your are syncing with exchange over the air, but it does give you the ability to propogate the checked items to other PCs when you sync with the cable.

Thanks again to Sansil. Truly awesome find!

kbcherry · 06/23/2008, 04:39 PM

Additionaly, this registry change is also needed if you want to successfully synch two devices to the same Exchange Server source. For example, I have a Treo 750 as well as a Tilt. I set up the Tilt as primary and then made this change on my 750. Now when I make a change on my Tilt (calendar, contacts or email) the next time I swap out my sim to the Treo the Treo automatically gets updated to show the same.

fastlerner · 06/24/2008, 10:04 AM

Quote:

Originally Posted by kbcherry

Additionaly, this registry change is also needed if you want to successfully synch two devices to the same Exchange Server source. For example, I have a Treo 750 as well as a Tilt. I set up the Tilt as primary and then made this change on my 750. Now when I make a change on my Tilt (calendar, contacts or email) the next time I swap out my sim to the Treo the Treo automatically gets updated to show the same.

If I'm not mistaken, that SHOULD happen anyway. In your case, you're talking about 2 separate WM devices syncing with the same exchange account. Since each device syncs with exchange independently of each other, a registry change on one device should have no impact on what the other does. It's really no different than having 2 different computers syncing to the same exchange account.

The reg change allows the WM device to propogate exchange changes when syncing with a copy of outlook that is NOT on exchange.

kbcherry · 06/24/2008, 04:53 PM

I understand what you are saying, but in my case it would not work. I did some research and found the same registry change as a fix for that problem. In theory it may sound like two computers accessing exchange, but in fact it is different since you are using active synch over the air. Either way, it wouldn't work. I made this change and it works flawlessly.

fastlerner · 06/24/2008, 05:25 PM

Hmm... Interesting.

I assumed that the over-the-air sync would be tied to the device somehow. But I guess what you're saying makes sense if you think of the sync as tied to the SIM. In that case it makes perfect sense that the cross-pollination setting would affect the ability to sync with multiple devices (when using the same SIM).

Learn something new every day.

neils31 · 03/26/2009, 12:20 PM

Hello,

I have being try to set up two exchange accounts on my WM6 device, but it doesnt seem to work.

I have two accounts, both for work, one is mine, the other is the office account.

I use my account wirelessly no problems, but when i try to add the office account using the method above, I get the error 'only one exchange account can be used" ...

can anyone offer some advice ?

Thanks
Neil

sansnil · 03/26/2009, 12:27 PM

Quote:

Originally Posted by neils31

Hello,

I have being try to set up two exchange accounts on my WM6 device, but it doesnt seem to work.

I have two accounts, both for work, one is mine, the other is the office account.

I use my account wirelessly no problems, but when i try to add the office account using the method above, I get the error 'only one exchange account can be used" ...

can anyone offer some advice ?

Thanks
Neil

Did you make the registry setting change as detailed above?

I'm also not sure this applies in WM6 as I only tested in WM 6.1.

neils31 · 03/26/2009, 12:30 PM

Sorry I should have said, the EnableNonLocalCrossPollination DWORD Data is 1

also I am using WM6.1

sansnil · 03/26/2009, 12:59 PM

Quote:

Originally Posted by neils31

Sorry I should have said, the EnableNonLocalCrossPollination DWORD Data is 1

also I am using WM6.1

Wow, that's very strange as it should work then.
Did you reboot after changing the registry setting and verify it's still at 1?

The only other thing I can thing to try is to delete both of your ActiveSync accounts from the device and then reboot.

Then first add back the account which you want to sync wirelessly.
Then sync once with the local computer - it shouldn't give you that error message but it won't have any options you can check to sync.
Once you've done the initial sync with your local computer, disconnect the device from activesync and modify the sync settings through the ActiveSync program on your phone.
Then if you resync with the local computer it should work.

neils31 · 03/26/2009, 01:15 PM

setting is still 1.

I have deleted all accounts then rebooted.

then connected to laptop and set up exchange account and sync'd.

i now have exchange account also windows pc1 account.

I then sync'd with desktop and created windows pc2 account, disconnected from desktop and tried to alter settings of pc2 account in device activsync.

I got the error :- you can only sync email with one source. to sync with win pc2 you must clear the email check box for exchange account.

and just checked again, reg entry is still 1

sansnil · 03/26/2009, 01:22 PM

Quote:

Originally Posted by neils31

setting is still 1.

I have deleted all accounts then rebooted.

then connected to laptop and set up exchange account and sync'd.

i now have exchange account also windows pc1 account.

I then sync'd with desktop and created windows pc2 account, disconnected from desktop and tried to alter settings of pc2 account in device activsync.

I got the error :- you can only sync email with one source. to sync with win pc2 you must clear the email check box for exchange account.

and just checked again, reg entry is still 1

Ahhh, now I think I understand. I don't know what you can sync multiple email accounts even with the cross-polination enabled. You can multiple synch calendar entries, tasks, contacts, and notes (I think notes I don't do that one) but not email I believe.

neils31 · 03/26/2009, 01:26 PM

Bah, thats just my luck ......

I can select the other options without error, but I only want the email ...

thanks for your help, much appreciated.

Pump Meister · 04/03/2009, 02:56 AM

I want to somehow figure out how to continue to sync my 750 with my home laptop (BT/cable sync) plus sync it with my work laptop at my new job where they use MS Exchange. Any suggestions or pointers?

Regards,

Steve

terra · 06/10/2009, 02:06 AM

works great many thx!!!!!!!!!!!!!!!!!!!!1

doctor15 · 06/28/2009, 02:00 PM

So does this change allow you to sync two exchange accounts OTA, or just one OTA and one through your computer?

What I would love to do is be able sync to my work exchange account OTA and use activesync for my Google Calendar/Contacts OTA.

I'm also not sure what the expected behavior of this would be. I want to make sure my personal Google Calender info doesn't appear on my work exchange server. If I could set it up to do one-way syncs, that would be great!

Any help is appreciated.

Gameboy70 · 07/04/2009, 02:52 AM

Would it be possible to sync 3 computers between 2 Exchange accounts using this method? I have a work PC on the company's Exchange server; then I have a personal laptop and home desktop I'm trying to get on my personal hosted Exchange account. Ideally, I'd like to sync both servers OTA, but I don't know if that's considered "more than 2 PCs," and therefore exceeding ActiveSync's client limit. Another approach would be to sync my home desktop and laptop OTA on my personal Exchange, and do a local ActiveSync at work. Would either of these schemes work if I made the registry edit? Thanks in advance.