Hello - I'm experiencing a very interesting situation.Background:We have 3 Servers each running a role in our Exchange 2007 environment. One Hub Transport, one Mailbox, and one Client Access server. We have several remote sites which used to all have an Exchange 2003 server. We have upgraded to 2007 and centralized the storage of mailboxes to the corporate office. Each site has roughly a 2mb connection to the corporate office.Problem:One site is experiencing connection issues to outlook. They are running cached-exchange mode with outlook 2003. Only one site is reporting issues. Everyone else is having no issues. And looking at the data in the packet shapers, only this site is maxing out their 2mb with Exchange traffice. All the other sites might hit 35KB or so. With that being said, I do know that the site having issues periodically sends out emails to the "All-Employees" group which could contain lets say 100 active and logged in users at a time. So for example, a couple of days ago, one employee sent a 37MB email to the all employees group. Of course this is going to cause issues because he is sending 37MB across the WAN and then once everyone's outlook profile is notified by the exchange server (15 seconds by default) that there has been a change in their mailbox, everyone's outlook (lets say 100 concurrent people) will try to download that 37MB. (at least that's how i'm thinking it works).SurelyMicrosoft has thought of this issue. I would think Microsoft would have an enterprise solution within their Exchange environment.By 'enterprise solution' i mean a centralized strategy to effectively give users the ability to use email. Surely this would involve NOT taking down a WAN connection.Question:Does anyonehave any ideas on what could be causing this ONE site the issue described above? If it is because they have their email over WAN, how come they are the only site having issues. We have other business units comperable in sizethat have no issuesat all. Is sending a 37MB attachment to an 'All Employees' group the one and only cause of this situation - is it even a cause at all? If a 37MB attachment to an 'All Employees' group is an issue, is there a solution to keep 100 people (as described in the example above) from simultaneously downloading 37MB of data over the WAN? Is there a way tocache attachments or large emails on a local server if that is an issue so when users send out attachments to massive amounts of people, the users are not downloading that attachment over theWAN?If anyone has any ideas, it would be greatly appreciated.ZachZach Smith

I would setup a network monitor and see what else is going through that pipe. sending a 37 meg attachment is not really a good idea in Exchange. Users should use SharePoint or FTP or something else rather then Exchange. You really want to keep the attachments under 10megs.It is possible that there is a backup running? Does that remote site have any other type of file server out there? SQL? etc? that could be causing the bandwidth issue? It could also be related to the number of users.You could always deploy a H/C and MB server out there for that one site.BP

Thanks for the reply. After further investigation, it was determined that the routers were losing adjancies with the core switch. This was caused by one of the ethernet cables on one of the LAN interfaces was disconnected. Apparently the IT staff at this location moved some equipment around 3 weeks ago and this was the same time the issues started, which was also the same time they got migrated to Exchange 2007 from their local 2003 server. An amazing coincidence, but all caused by a LAN interface not having a cable plugged in. It was 'half-way' plugged in. go figure.thanks.Zach Smith