Microsoft has released service pack 2 for exchange 2007 server and is available for download here Exchange 2007 SP2 includes the necessary schema extensions for Exchange server 2010.

Download the SP2 release notes from here

Take a note of the following before installing SP2, which is mentioned in the release notes.

• You need Windows 4.5 Installer before you can install SP2. Operating systems apart from Windows 2008 SP2 needs to download and install it.
• SP2 cannot be selectively uninstalled. You will have to uninstall entire exchange and install it again with a previous version.
• Install SP2 in the following order – CAS, UM, HUB, EDGE, MBX.
• You can upgrade servers running RTM as well as SP1 to SP2 version.
• You can upgrade either using the GUI or command line (Setup.com /mode:upgrade)
• After installing SP2, you can have 2007 in co-existence with 2010 RC (in your lab, ofcourse!)

Service Pack 2 for Exchange Server 2007 is to be released today as per a post by Paul Bowden (Exchange Release Manager) in 2010 Technet Forum.

Once the US guys wake up, download links and information should be published. It’s Henrik Walther who spotted the information in the post. More info here

Address Rewriting is a feature that is supported only in 2007 Edge servers. It is the process of rewriting the sender address with one of your choice. It is extremely helpful in merger situations when two companies which has their own email domains want to send emails from a third common email domain. Though it is possible to find out the true origin of the email, most of the header information are rewritten except the Received and Message-ID headers. These are not readily visible for the recipients and hence the address rewrite does work.

Address Rewriting is achieved using two transport agents, Address Rewriting Inbound Agent and Address Rewriting Outbound Agent. First step is to make sure that these agents are enabled. To do so, run the command Get-TransportAgent on the edge server.

If the agents are not already enabled, enable it by running Enable-TransportAgent –identity “Address Rewriting Inbound Agent” and Enable-TransportAgent –identity “Address Rewriting Outbound Agent”. Once the agents are enabled, you can configure the address rewrite using the New-AddressRewriteEntry cmdlet.

In order to change the address of all emails from @howexchangeworks.com to @rajith.com, run the command New-AddressRewriteEntry –Name HEWtoRajith -InternalAddress howexchangeworks.com –ExternalAddress rajith.com

Restart the Exchange Transport Service if it doesn’t work straightaway. You can have more than one address rewrite entries and can even rewrite a single address like rajith@howexchangeworks.com to rajith@rajith.com, by replacing the domain name with the email address in the New-AddressRewrite cmdlet.

SMTP Tarpitting is enabled by default in Exchange 2007. This is really good news as admins who configure recipient filtering are automatically protected against directory harvest attacks. This was not the case in exchange 2003, as a registry edit was necessary to enable the feature. Check this KB article for information regarding how to enable tarpitting on an exchange 2003 server.

SMTP Tarpitting is the feature by which a delay is introduced to the rejection response. When a recipient is rejected with a 5.x.x response, a delay of few seconds is introduced before the response is initiated. This makes it difficult for spammers to find legitimate email addresses in a domain by using directory harvesting attacks.

Exchange 2007 has a default tarpit interval of 5 seconds, which can be increased upto a maximum of 10 minutes. Much thought should be put in while changing the tarpit interval, as it will affect legitimate emails as well (the ones that are not spam, like misspelt addresses). The default interval is good in most cases. Tarpit interval is set on the receive connector and is in the format hh:mm:ss.

In order to find the tarpit interval, run the following command

Get-ReceiveConnector connectorname | select tarpitinterval

To increase the tarpit interval to 10 seconds, run Set-ReceiveConnector connectorname –TarpitInterval 00:00:10

Run Set-ReceiveConnector connectorname –TarpitInterval 00:00:00 to disable tarpitting (not recommended).

Exchange 2010 RC is feature complete and available for download. Download it from here

You can install the 2010 RC on Windows 2008 SP2 X64 and Windows 2008 R2 X64 editions. It cannot be installed on earlier versions of windows. In place upgrade of 2010 RC version to 2010 RTM is supported. The evaluation edition available for download is an enterprise edition and hence can be upgraded to 2010 Enterprise RTM (and not a standard RTM).

In place upgrade from 2010 Beta to RC is not supported.

Exchange 2007 comes with a new feature for monitoring the resources on the transport servers known as Back Pressure. The feature runs only on hub and edge transport servers. Exchange Transport Service is responsible for the running it.

The following resources are closely monitored by the Back Pressure feature.

1. The available disk space on the drive that has the transport database (Mail.que).

2. The available disk space on the drive that has the transport database log files.

3. Memory used by all processes

4. Memory used by EdgeTransport.exe process.

5. Number of uncommitted transport database transactions  in the memory, known as Version Buckets.

There are three levels for the status of these counters – Normal, Medium and High. Each of the levels have pre-defined threshold values for each counter that is being monitored.

Typical symptoms of Back Pressure feature being kicked in is when you have emails stuck in the Drafts folder or get a “4.3.1 Insufficient System Resources” ndr from exchange.

For example, the available disk space on the drive that has the transport database should be atleast 500mb. If it goes below that level, the transport servers stop sending and receiving emails. The available space threshold was 4gb for pre SP1 servers, which was bit of an overkill. Similarly, all resources that are monitored has a pre-defined threshold limits.

Can we change any of these settings? Of course you can! All settings related to the back pressure feature is stored in edgeTransport.exe.config file which is located in the bin directory. By default, it is in C:Program FilesMicrosoftExchange ServerBin. Open the config file in notepad and have a look at the settings & change any if needed. The Transport Service will have to be restarted for the changes to take effect.

Can we disable Back Pressure feature altogether? And the answer is yes! You can edit the config file with the entry “false” for , save the file and restart the transport service. Job done! It is not recommended to disable the feature as it will be useful for to know when resources are running out. If you want some time to sort out the resource issues like increasing the disk space available but keep the server operational at the same time, disable the feature, fix the resource issue and enable it again.

Can we change the resource monitoring interval? The default interval is 2 seconds. You can modify the value with anything between 1 and 30 seconds. Edi the config file with the value of your choice for the entry , save the config and restart the transport server.

An important point to note is that the back pressure feature is only available for hub and edge transport servers. Check this article for more information regarding changing the back pressure settings.

A clear understanding of how the offline address book works in exchange helps an admin in troubleshooting the related issues. This article explains how oab works in the 2007 edition.

The Exchange System Attendant service is responsible for the generation of oab. This service is available only on a server that has the mailbox role installed. The SA invokes a dll file called oabgen.dll. To find out the server that is generating the offline address book, launch EMC –> Organizational Configuration –> Mailbox –> OAB tab.

Once you have made too many changes in exchange, you can update the address book by right clicking and selecting Update. By default, oab is updated only once in 24 hours at 5am. You can customize the update schedule depending upon your requirements.

Where exactly are these oab files stored? On a default installtion, the oab files are stored in C:Program FilesMicrosoftExchange ServerExchangeOAB. This folder is shared so that it can be replicated to the CAS server for web distribution.

How does oab end up in public folders? Outlook 2003 and previous versions get oab from the system public folders in exchange. The oab generation server opens the oab folders and updates the file. The oabgen.dll file is responsible for connecting to the public folder.

How does Outlook 2007 get oab files? The server that has the client access role installed (CAS server) is responsible for providing oab files for outlook 2007 clients. For that, CAS server runs a service named Microsoft Exchange File Distribution Service which copies the oab files from the mailbox server (ExchangeOAB folder) to the web distribution point in the CAS server.

Where is this web distribution point, one might ask? The web distribution folder is a folder in the file system where the copied oab files are placed. The default location is C:Program FilesMicrosoftExchange ServerClientAccessOAB.

The web distribution point is updated once in 8 hours. If you want to force an oab update, restart the Exchange File Distribution Service.

Now that you know how oab works and are replicated from the mailbox server to the system folders and web distribution point, you will find it much easier to troubleshoot any issues relating to the offline address book.

OWA 2010 gives a new view for emails by default, which is termed “Conversation View”. It will be the same in Outlook 2010 as well.

The view that we are used to in all versions of outlook and OWA till date is “arrange by date”. A snapshot is shown below.

The conversation view sorts all these lengthy emails by conversation. So, all the emails shown above is shown as a single entry.

You can expand the emails and it will shows a snapshot of all the replies that has come for that conversation.

Database Availability Group (DAG) is the new high availability solution in Exchange 2010. None of the clustering technologies in 2007 is valid in 2010.

DAG is a collection of upto 16 mailbox servers with a maximum of 16 copies of each database. It makes the database independent of any server and gives us failover on a mailbox level rather than a hardware or storage group level as in 2007. To illustrate it, if one database gets corrupted or the disk having the files fails, you can quickly mount a copy of the same database in any of the servers which is part of the DAG.

Follow the steps to create and configure a DAG.

Launch EMC 2010 and navigate to Organization Configuration –> Mailbox –> Database Availability tab. Right click anywhere on the pane and select “New Database Availability Group”. You can also select the option from the action pane.

You need to specify the name of the DAG (this will appear in EMC), the file share witness unc path (similar to 2007) and the location of the FSW folder. Exchange will create the folder and hence specify the path as to where you want the folder to be. Microsoft recommends to have the FSW on a hub server.

Click New and Finish. You will see that the DAG is now listed in EMC.

The creation of DAG will only create an AD computer object, which is visible in AD Users and Computers.

Just having a DAG created is no good to us. Now, we will add the first node to the DAG. Right click the DAG in EMC and click on “Manage DAG Membership”.

Select the first server to be part of the DAG and click Manage.

 

Using the console for adding the first server gave me the error below stating that “Insufficient permissions to view the network shares on the machine, Error Code 5”.

The problem here is that remote powershell is used in the background which is causing the error. It is a known issue and should be corrected in the final release. I launched the Local Powershell and ran the same command which the console ran and everything was fine.

Add-DatabaseAvailabilityGroupServer –identity HEWDAG –MailboxServer E14Node1

As you can see, the shell installs Windows Failover Clustering as part of configuring the server to be a member of DAG. You don’t have to install clustering before hand as the process will go ahead and install if it is not present. This is good for admins who are not that comfortable with configuring the cluster themselves, like CCR in 2007.

Once the server becomes part of the DAG, more information is made available in the console.

The failover clustering quorum settings will be set to “Node Majority”.

In order to add the second server E14Node2 to the DAG, I launched the Local Powershell from the second server and executed the same command which we ran earlier.

Add-DatabaseAvailabilityGroupServer –identity HEWDAG –MailboxServer E14Node2

Once the second node is added, the quorum setting is automatically changed to “Node and file share majority”.

The file share witness is only created once the second server is added to the DAG as the quorum setting is only changed at that time.

The EMC will now show both the servers as part of the DAG in the EMC.

That is it. We now have a working DAG. I will explain the database copy and failover functionality in a different article.

As more and more people have started to play with the beta version of Exchange 2010, let us see as to what is new and what has changed in the 2010 Mailbox role.

1. There is no LCR, CCR, SCC or SCR high availability options in Exchange 2010 mailbox server.

2. There is no clustered (Active or Passive) mailbox installation option in 2010 setup.

3. You can have other roles installed on a 2010 mailbox server even if it is a part of Database Availability Group.

4. There is no Exchange Virtual Server (EVS) or Cluster Mailbox Server (CMS).

5. There are no storage groups in 2010. Instead, mailboxes are now organizational level objects.

6. Database is no longer “tied” to a server, if DAG is implemented.

7. Database name should be unique in an exchange organization.