+ a billion OP is talking 2007 so I don't know if this applies or not (we skipped over 2007) but as far as 2010 and cached mode-
If you're creating/changing message retention tags/policies during a migration (or I guess at any time) you might want to stagger the application of the policies to the mailboxes. Applying a tag to a message means a change to the message and that of course means a resynch. We learned quickly that we could migrate a few hundred mailboxes from 2K3 to 2K10 overnight. We also learned quickly that it wasn't a good idea to apply the retention policies to all those mailboxes at once:) Wasn't a terribly big deal on our fast links but on the slower ones, hoo-boy... From: Michael B. Smith [mailto:mich...@smithcons.com] Sent: Thursday, January 06, 2011 11:51 AM To: MS-Exchange Admin Issues Subject: RE: Outlook 2007 Cached Exchange Mode Best Practice And load on the OAB servers. Like Rob said - stage it. Regards, Michael B. Smith Consultant and Exchange MVP http://TheEssentialExchange.com From: Webster [mailto:carlwebs...@gmail.com] Sent: Thursday, January 06, 2011 11:37 AM To: MS-Exchange Admin Issues Subject: RE: Outlook 2007 Cached Exchange Mode Best Practice Bandwidth. Webster From: Tu, Kevin [mailto:k...@ccscorporation.ca] Subject: Outlook 2007 Cached Exchange Mode Best Practice Hello, It seems turning on Outlook 2007 Cached Exchange Mode is a best practice. http://office.microsoft.com/en-us/outlook-help/best-practices-for-outlook-2007-HA010371521.aspx The first step in following these best practices is to set up a system to optimize how you use Outlook 2007. It is considered best practice to have the following: ... Cached Exchange Mode turned on. http://msexchangeteam.com/archive/2007/01/15/432199.aspx Outlook 2007 in Cached Mode is important for reducing server I/O as much as 70% over Exchange 2003. The initial mailbox sync is an expensive operation, but over time, as the mailbox size grows, the disk subsystem burden is shifted from the Exchange server to the Outlook client. We have 2000+ Outlook 2007 clients with half laptops and half desktops. Are there any considerations or side effects if we turn on Cached Exchange Mode companywide? --- To manage subscriptions click here: http://lyris.sunbelt-software.com/read/my_forums/ or send an email to listmana...@lyris.sunbeltsoftware.com<mailto:listmana...@lyris.sunbeltsoftware.com> with the body: unsubscribe exchangelist --- To manage subscriptions click here: http://lyris.sunbelt-software.com/read/my_forums/ or send an email to listmana...@lyris.sunbeltsoftware.com<mailto:listmana...@lyris.sunbeltsoftware.com> with the body: unsubscribe exchangelist --- To manage subscriptions click here: http://lyris.sunbelt-software.com/read/my_forums/ or send an email to listmana...@lyris.sunbeltsoftware.com with the body: unsubscribe exchangelist