Hello I understand that Exchange pulls AD information from DC's via the DS Access process. At the same time, the Exchange holds information in the Information Store (IS Cache)... Does anyone know what different types of information are held in the two? I assume DS Access cache is the result of GAL lookups etc, but how about information on mailbox storage limits etc? For instance, if I give a user send on behalf access to another's mailbox, or give someone permission on a restricted DL, which cache is actually checked? This would help us work out how long we should allow for the changes to propogate since I understand that DS Access cache is 5 mins and the IS Cache is 2 hours!

Check out: http://social.technet.microsoft.com/Forums/en-US/exchangesvrgeneral/thread/2188ca43-39db-44db-bd60-1a0832d5dcd9

Thanks Andy, I've read that post but it doesn't answer my question:" For instance, if I give a user send on behalf access to another's mailbox, or give someone permission on a restricted DL, which cache is actually checked? This would help us work out how long we should allow for the changes to propogate since I understand that DS Access cache is 5 mins and the IS Cache is 2 hours!"

Well, if you read that article linked: http://technet.microsoft.com/en-us/library/bb684892.aspxYou'll see that you really need to take both values into consideration.If you modify the Reread Logon Quotas Interval to the recommended time of 20 minutes, then you'll know that the longest any change will take will be 20 minutes :)

Excellent David, thanks very much.Do you know about the permissions side (e.g. adding someone as 'Send on Behalf', adding user to a restricted DL etc)... Also, in the Comments section of http://technet.microsoft.com/en-us/library/bb684892.aspx, some people say that moving a user's mailbox to a different store would refresh the Logon Quota cache in the IS cache, any idea why this is?Thanks again.

Hi, Please understand when the Store needs to access information from Active Directory, it will ask DSAccess to perform this task on its behalf. Therefore, both the DSAccess cache and the IS cache will affect the mailbox storage limits. Regarding the Comments method "Move Mailbox", I do not think that it is a recommended method. Microsoft recommend that you change Reread Logon Quotas Interval value to force refreshing IS cache more freqently:Note: If you set the cache refresh intervals to very low values, you may affect the performance of your Exchange server. We recommend a value of 20 minutes for refreshing the mailbox information. Thanks,Mike

Agreed with Mike.Sheen, when moving mailboxes, the quota gets reevaluated for that mailbox, that's why it gets enforced immediately.