Windows 7 Forums
Welcome to Windows 7 Forums. Our forum is dedicated to helping you find support and solutions for any problems regarding your Windows 7 PC be it Dell, HP, Acer, Asus or a custom build. We also provide an extensive Windows 7 tutorial section that covers a wide range of tips and tricks.

Windows 7: Microsoft Lifting the 500 Folder Limit in Outlook

04 Jun 2019   #1

64-bit Windows 10 Pro
Microsoft Lifting the 500 Folder Limit in Outlook

Hi – I’m Jon LeCroy from the Outlook team, and today I have a story to tell you about the most requested and most rejected (sorry) feature in the history of Outlook.

The limit of 500 shared folders has been a longstanding product limitation in Outlook for Windows since the dawn of cached mode (2003!) For those with access to mailboxes containing more than 500 folders, sync would “randomly” fail resulting in an inconsistent sync for both the customer’s own mailbox, as well as the other mailboxes they had access to. This has been especially painful for those in roles supporting executives. If the executive has many folders, synchronization becomes unreliable for the person they rely on most.

Over the years, many customers have asked us to address this limitation, and understandably so given the impact. Unfortunately, when we looked at this we would find that it was a multi-year engineering effort to complete the changes necessary to rearchitect Outlook to avoid this.

Last fall, several customers each escalated this issue to us again, all at once. This prompted us to take a hard look at the feasibility of addressing this. Was this something fundamental to the design of Outlook and Exchange? Or was there was something we could do about it? Skipping forward to the obvious: we were able to find a way to fix this that avoids the years of work we believed this to take previously.

Technical Breakdown

For the more technical readers out there, I’ll indulge you with some additional detail. Exchange allows for what we call “deep hierarchy” notifications, these will notify the client if something changes within a given folder subtree. For the primary account mailbox, Outlook uses this at the root/top of the mailbox folders to do regular sync. We register the notification, Exchange tells us when something changes, and we sync down the changes.

For shared mailboxes however, this gets trickier. It’s prohibitively expensive (performance wise) in Exchange to evaluate access on a change by change basis to determine if the registered client has access to the item changed, thus deep hierarchy notifications are only available if you’re the mailbox owner. Until now, Outlook would keep each individual folder open and register for changes in that folder (“shallow” notifications) to learn when something changed. Pairing this behavior with Exchange’s default limits of 500 MAPI objects open at a time, and we have the 500 folder limit.

Fortunately, when we looked harder at our options we were able to find another means of learning that something changed in the folder hierarchy – a special property on the folder that is updated when anything within it changes. Now we watch for changes to this property on the shared mailbox, and when detected we’ll work through the shared mailbox to sync any changes. Voilŕ! Sync for shared mailboxes without running into the 500 folder limit!

So, what’s the new limit?

Since we’ve changed how shared mailbox sync works in a way that works smarter under the previous limitations (and didn’t simply raise the limit in Exchange) I don’t have a simple “new limit” to share with you. The new functional limit will be influenced by Outlook’s available resources and configuration. I am happy to report however that we expect a 10x increase (500 to 5000) for most customers!

These changes were released to our Monthly Channel (Targeted) customers with our May release, 1906 (11629.20136) and later, to our Monthly Channel customers with 1906 (11629.20196) and later, and will be coming to our Semi-Annual channel customers on the regular SA schedule (September for Targeted and January for general release.)

Thank you for reading and for your participation in the Insider program! If you have any issues in Outlook (with sync or anything else), please let us know by going to Help > Contact Support and we’ll be happy to help.

Source: Lifting the 500 Folder Limit in Outlook - Office Insider Blog

My System SpecsSystem Spec

 Microsoft Lifting the 500 Folder Limit in Outlook

Thread Tools

Similar help and support threads
Thread Forum
Is There a Limit to the Size of a My Documents Folder?
Confession: I've only recently installed Windows 7/Pro x64. I tried using Apache Open Office Writer, saving my documents in the Microsoft *.doc format. A few days into the evaluation I tried to save a file and discovered that a branch in my "My Documents" folder had disappeared. I tried...
Microsoft Office
Microsoft Outlook 2010 Sound for Empty Folder for Deleted Items
Hi, Can anyone tell me how I can get a sound for Empty Folder for Deleted Items? I am sure I had a sound and now I don't. Thank you.
Browsers & Mail
Outlook 2010 message size limit
Ever since office 2010, its required a registry edit to send files larger than 25mb.... well, I tried using the reg edit and it isn't working any longer (at least not for me). Anyone have a fix for this? And this is on any email account, I know it is not a limit on the server.
Microsoft Office
Folder Limit
I hope that this is the right section for this =P I am wondering if I can set limits on a folder and how much space it can take up on my system. I would like to keep a folder from going over 7GB. Is there any program that I can do this with to customize the folder that way? ( or something else ? )...
Microsoft to bin “three app limit” on Windows 7 Starter
Read more

Our Sites

Site Links

About Us

Find Us

Windows 7 Forums is an independent web site and has not been authorized, sponsored, or otherwise approved by Microsoft Corporation. "Windows 7" and related materials are trademarks of Microsoft Corp.

© Designer Media Ltd

All times are GMT -5. The time now is 23:44.
Twitter Facebook