ZEQL

Exchange 2007 introduced a helpful new feature caleld transport rules. I’ve given presentations on some of the cool things you (or the Duke boys) can do with Exchange transport rules at conferences… I’ll see about transitioning some of that information to this site in the future.

One of the ‘gotchas’ related to Exchange 2007 transport rules is the ammount of time required for replication.  It doesn’t really get too much attention when Microsoft (or others) are discussing some of the theoretical uses for transport rules. Let’s say that you needed to implement a transport rule to add a link to the latest company press release on all outbound mail. The CMO calls at 8AM and wants the change to be in place by noon. Ignoring the possible change control issues, can you modify your outbound signatures in time?

The answer? It depends.

The first concern is that transport rules in Exchange 2007 are stored in Active Directory. As a result propagation of changes is predicated on AD replication for your topology. In a small, single server Exchange environment odds are AD replication won’t be a factor. but in a large or multi-national organization AD replication could easily take a day (or 2 if they are using AD lag sites).

Microsoft mentions this in a TechNet article on Transport Rule application:

Important:
Replication of transport rules across an organization is dependant on
Active Directory replication. Replication time between Active Directory
domain controllers varies depending on the number of sites in the
organization, slow links, and other factors outside the control of
Exchange. When you configure transport rules in your organization, make
sure that you consider replication delays.

The other area of potential concern is the Hub Transport server cache. Rather than quering each rule against AD every time it is applied, the Hub Transport server caches the results from AD for 4 hours before checking again for changes to the rule. So a request at 8AM could take up to 4 hours to take effect even in a single server environment. (Although restarting the Microsoft Exchange Transport Service will force an immediate requery and assuming the AD replication has taken effect the transport rule changes will take effect).

Important:
Each Hub Transport server maintains a recipient cache that is used to
look up recipient and distribution list information. The recipient
cache reduces the number of requests that each Hub Transport server
must make to an Active Directory domain controller. The recipient cache
updates every four hours. You can't modify the recipient cache update
interval. Therefore, changes to transport rule recipients, such as the
addition or removal of distribution list members, may not be applied to
transport rules until the recipient cache is updated. To force an
immediate update of the recipient cache, you must stop and start the
Microsoft Exchange Transport service. You must do this for each Hub
Transport server where you want to forcibly update the recipient cache.

So, total replication time for a transport rule change could be max AD replication interval for your organization plus 4 hours.

There are occasions where an Exchange server’s queues may fill. If those messages are junk, NDRs, spam or relayed messages it may be desirable to delete those messages en mass. Using the ESM UI can be painful at best. If there are thousands of destination domains there is no easy way in the UI to delete these messages. Selecting each queue in turn can take hours to complete. Enter aqadmcli.exe a utility available for download from Microsoft. Using aqadmcli.exe thousands of queues filled with NDRs can be cleared with a single command:

aqadmcli.exe “delmsg flags=SENDER,sender=postmaster@example.com“ Read the rest of this entry »

Microsoft has released update rollup 5 for Exchange 2007 SP1.

One of the fixes was for an issue that impacted a number of my customers:

951273  (http://support.microsoft.com/kb/951273/ ) The received date and the received time of IMAP messages are changed to the time of migration after you migrate mailboxes to an Exchange 2007 Service Pack 1-based server.

Download: http://www.microsoft.com/downloads/details.aspx?familyid=652ed33a-11a1-459c-8ffe-90b9cbfe7903&displaylang=en&tm
Fixes: http://support.microsoft.com/?kbid=953467