I had a few questions come up related to how the task synchronization works between OneNote 2007 and Outlook. This is actually one of the best features that was added in OneNote 2007, as I noted in my post on “EverNote vs. OneNote“. The task synchronization feature, however, is still pretty new and can be easily broken. If you want to know how to synch without getting sunk, read on… (Ok, bad pun, sorry for that.)

The screenshot below shows a typical project in OneNote (from my OneNote Project Template). You can see that some tasks have a dark red flag, and some have a faded red flag. The faded red flag either means that the due date is farther out, or that OneNote hasn’t found the task in Outlook yet to determine the due date. Sometimes it just takes OneNote a minute or two to search Outlook and those pale flags turn back into dark red. Other times (such as when a task is moved to another folder or deleted in Outlook), OneNote never finds the task.


So how is OneNote finding those tasks in Outlook? Although I’m not an expert on the inner workings of OneNote, I did some snooping into the OneNote-to-Outlook interface. I say “snooping” since “reverse-engineering” would be a bit too strong for the 20 minutes I looked at this. Anyway, here is what I found… Basically, OneNote is adding two custom fields to your tasks: OneNoteTaskID and OneNoteURL. If you open the Field Chooser in your Outlook Tasks folder, you can see these fields listed under “User-defined fields in folder”. If you add these fields to your view you can get a peek at the contents. This is shown in the screenshots below.

OneNote also sticks a file into the created task as an attachment. This is a binary file with a “.one” extension. If you double-click on the file it takes you back to the line in OneNote from which the task was created. This is really just for your convenience, not something that is used as part of the automatic synchronization.


Generally speaking, the more tasks you have, the longer it takes OneNote to search. That explains why sometimes when you open up a project in OneNote, there is that delay before the flags go to full red. Until the task is found, the “Open Task in Outlook” menu option will be grayed out. The interesting thing is that you can still pick “Delete Outlook Task” from the context menu in OneNote. If the task is not found, this simply removes the flag in OneNote. You may still have a task floating out there in Outlook. This is one key weakness of the current task synchronization feature in OneNote 2007. For those of us that use multiple task folders in Outlook and like to move tasks around, the links get broken pretty quickly. In my previous post on “Bending OneNote and Outlook to Fit my GTD System“, I talked about using this feature to get next actions from the project page into the Outlook task list. Because of this weakness, I basically don’t worry too much what the status shows in OneNote. As soon as it’s moved to Outlook it gets tracked through to completion there. I may manually update the task status on the project page during my weekly review, but that’s just for reference since the real task is now in Outlook.