Outlook 2016 cached mode gal not updating

With Office 365 in particular, Microsoft will not prevent you from using online mode, but if performance is poor and you call support, they will instruct you to use cached mode.

For the rest of you, consider the following – if you do any of these, online mode may provide the better experience for your users: Ultimately, I tell all my customers to use cached mode, and if they cannot for any reason, to use OWA instead of Outlook.

Companies using Exchange Server are often confused around whether they should run cached mode or online mode on their Outlook clients.

In this post, we are going to look at just what the differences are, and make some recommendations on when each is appropriate.

Cached mode, which first came out with Microsoft Outlook 2003, keeps a local copy of the user’s mailbox stored on the hard drive as an OST file.

Running in cached mode, the Outlook client looks to the local OST file for all access, including reads and searches, while a separate process checks for new mail on the server and syncs data to the local cache.

I disagree with the general opinions about risks associated with using OST files.

If you have a machine that leaves the physical security of your four walls, then you have a data risk no matter whether you use cached mode or online mode.

If you are seeing client connections to the CAS server go over that consistently, you might want to switch to cached mode.

You should user online mode when users have no persistent storage to which they can store their OST, such as VDI scenarios or on devices with limited storage capacity, such as tablets.

You may also use online mode for extremely large mailboxes to improve overall performance, or where you do not want to risk having a local copy of the OST for compliance or other reasons.

Don’t fear the OST; instead, embrace full disk encryption such as that offered by Bit Locker or various third party vendors, and ensure strong authentication is required to gain local access to the disk.

It’s far better to secure all the data, then to shoot yourself in the foot with regards to Outlook performance.

Leave a Reply