Hello, I have set the default mailbox size to 290/295/300(warn/block send/block send receive) on our mailbox db. I've also set other users to overide those settings with either smaller or larger sizes. It seems like nothing is being enforced. We have users in all three scenerios that are over their limit. They are not receiving any warnings, blocks, etc. any ideas? Thanks.

You can use EMS to check mailbox quota, Please reference this article Interpreting Status of Storage Quotas via Exchange Management Shell

Thanks.

Is there no way to set the mailbox quotas at the server level instead of each store or am I misunderstanding something?

How long did you wait after setting the limits? It will sometimes take an hour or two for the limits to be put in place. Exchange only reads the limit settings every 2 hours (I think that is right) from the Active Directory.

below post will help you: http://msexchangeteam.com/archive/2006/09/20/428965.aspxDinesh