Drawbacks and Benefits in using chched mode of Outlook 2007

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We are a large corporate Organisation and have just completed the full deployment of MS Office 2007 to approximately 3,000 Users. We are now considering pushing-out (via the Network), Cached Mode of Outlook 2007 and am trying to pre-empt a few questions Users may raise with our IT Service Desk.

What does cached mode mean? What happens if my Laptop is unplugged from the Network, can users access my mails?Does caching include: Mail, Calendars, Appointments, Notes? How does this affect you if you access shared Mailboxes? Can you draft emails while unplugged from the Network? What are the security implications? What happens if there is a Disk failure when emails are cached? Is a copy of the cache kept on the Server? Is there a limit on the numbers of emails that can be drafted in cached mode and disconnected from the Network?Is there a limit on the time that the cached Mailbox can be disconnected from the Network?Are there any problems that other Users/Sites using Cached mode have encountered?Are there any other drawbacks?

Diane Poremsky

Senior Member
Outlook version
Outlook 2016 32 bit
Email Account
Office 365 Exchange

See http://office.microsoft.com/en-us/outlook-help/about-cached-exchange-mode-HP001000067.aspx

Are you familiar with IMAP accounts? Cached mode is like this, in that it keeps a copy locally and mail remains on the server. If the desktop disk dies, they'll resync the mailbox from the server.

The biggest benefit (IMHO) is when the network is down or the user unhooks a laptop,*all* mailbox data is available to the user. "can users access my mails?" - mailbox owners can access mail which was previously downloaded to their outlook. They can't send new mail (but can compose it and it gets sent when they connect to the server) or access newly delivered mail until they reconnect. There is no time limit for disconnection from the network and there is no limit to the amt of mail your outbox can hold while it waits to reconnect.

Shared mailboxes can be cached - i think in 2007 you'll only get shared calendars - the dialog in the Account's More Settings will say for sure.

The biggest problem sites encounter with cache mode is how long it takes for large mailboxes to sync.


Ben M. Schorr [MVP]

Cached mode is also better for performance - both at the workstation and at the server. And without cached mode the client-side junk e-mail filters don't work.

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