Exchange Management Shell

It may first appear as if the Exchange Management Shell is nothing more than a standard command prompt. But if you look at its prompt, you will notice that the letters "MSH" appear in brackets just ahead of the path.

The [MSH] tells you that you are not running in a true command prompt environment, but rather within a Microsoft Scripting Host shell. The Exchange Management Shell is nothing more than a Microsoft Scripting Host environment that has been extended to support Exchange Server commands.

There are many management tasks that are only performed on the Exchange Managament Shell and CANNOT be performed in Exchange Management Console. Some of them are:

• All Public Folder management.
• Give permissions to user's mailbox, entire database or the server.
• Advanced database, mailbox and recipient management.
• Advanced Transport Settings like setting a maximum message size limit for incoming and outgoing messages on the organization or connector, Set advanced SMTP connection settings etc.
• Certain Client Access settings also like set connection time-outs for POP3/IMAP4 servers (Set-IMAPSettings / Set-POPSettings), Prevent previous versions of Outlook from connecting to Exchange (Set-CASMailbox –MAPIBlockOutlookVersions), Enable/disable POP3 or IMAP4 for a user (Set-CASMailbox) etc...

Here is some collection of scripts for managing Exchange Server 2007 that are very useful for day to day operation and management.

Sender Policy Framework (SPF)

The Sender Policy Framework (SPF) is an open standard specifying a technical method to prevent sender address forgery. It is an attempt to control forged e-mail. SPF is not directly about stopping spam – junk email. It is about giving domain owners a way to say which mail sources are legitimate for their domain and which ones aren't.

The current version of SPF — called SPFv1 or SPF Classic — protects the envelope sender address, which is used for the delivery of messages.

Sender authentication protocols are designed to protect against forgery of e-mail sender identities, either in the envelope or in the header. In the envelope, first there is the "HELO" identity, which names the mail server (MTA) that is sending the message. The "MAIL FROM" identity is the e-mail address that is responsible for sending the message and where delivery errors (bounces) will eventually be reported. And the "RCPT TO" identity is the message's recipient address. The header contains another set of identities (besides other meta information about the message, such as the subject and the sending date).

SPF authenticates the envelope HELO and MAIL FROM identities by comparing the sending mail server's IP address to the list of authorized sending IP addresses published by the sender domain's owner in a "v=spf1" DNS record.

SPFv1 allows the owner of a domain to specify their mail sending policy, e.g. which mail servers they use to send mail from their domain. The technology requires two sides to play together:
(1) the domain owner publishes this information in an SPF record in the domain's DNS zone, and when someone else's mail server receives a message claiming to come from that domain, then
(2) the receiving server can check whether the message complies with the domain's stated policy. If, e.g., the message comes from an unknown server, it can be considered a fake.

Example of SPF Record

mydomain.com. TXT "v=spf1 mx a:machine1.mydomain.com include:gmail.com -all"

The parts of this SPF record mean the following:

v=spf1: SPF version 1
mx: the incoming mail servers (MX's) of the domain are authorized to also send mail for mydomain.com
a:machine1.mydomain.com: the machine machine1.mydomain.com is authorized, too
include:gmail.com: everything considered legitimate by gmail.com is legitimate for mydomain.com
-all: all other machines are not authorized

For detailed information on SPF records and their syntax, please refer www.openspf.org
The SPF Setup Wizard: http://old.openspf.org/wizard.html

Troubleshooting Fast Growing Transaction Logs

Here is a pretty good technet that details various causes:

http://technet.microsoft.com/en-us/library/aa996191.aspx

Also when we mount/dismount the stores manually, the transaction logs files are replayed on to the database thus they get committed and we are able to mount stores.

We can check this status by using eseutil: eseutil /mk "path to checkpoint file"

It will give you the transaction log file uptill which all the logs have been committed. This is helpful in the case we are running out of disk space and when the full backup is also a long way to finish… so that we can move out the committed logs and keep them on a different location. In case of recovery scenario, we need these log files to make database up-to-date.

Disaster Recovery (Soft Recovery) - Exchange 2003

After an unexpected shutdown of the Exchange Server, the Information Stores in One Storage Group goes dismounted. Gave an error message while mounting.
Checked the state of the databases by eseutil /mh and there it shows dirty shutdown.

Here it can be that one of the database is not up-to-date and the server got rebooted when it was processing one of the transactions and got corrupted.

Our next step in this case is to identify the store that has been corrupted.

We will try to replay the logfiles on the each of the stores individually:

• Renamed priv2.edb and priv2.stb.
• Replayed the logfiles: eseutil /r /i E00
• Error Encountered. So log files cannot be replayed for Information Store 1 (priv1.edb, priv1.stm)
• Now Renamed priv1.edb and priv1.stm.
• Replayed the logfiles: eseutil/ r /i E00
• Completed Successfully. So the Information Store 2 is up to date now and we are able to mount it.

Now as the Information Store 1 is corrupted, the best practice is to restore from the last backup and then make the database up to date by recovering from the present log files.Eseutil /p should be the last resort as it performs the hard recovery and punches off the corrupted tables or entries from the database. So there is always a good chance of loss of some data.

As we have renamed priv1.edb and priv1.stm, the database restore from the backup will create new set of these files. We should not overwrite these files from the restore.

The Restore of backup (Veritas in this Case) should be set with the following options:

• Do not replay logs automatically
• Do not mount databases
• No Loss restore (don't overwrite or delete anything)
  

After the restore, we have the new set of edb and stm (a day old) and the current log files that will make them up to date.
Now we will use "ESEUTIL /CC" command to replay to restore.env file and continue on to production log files. There are temporary log files and restore.env file created when we run the restore. In case of Veritas restore, they are created in C:\temp\

Restore.env file is just a temporary environmental file holding path information about the data. Its purpose is to help the Exchange 2003 restore process find its files and match them with the corresponding email stores.

Now run the command eseutil /cc "path of restore.env"

Mount the store back after it completes successfully.

Calculate amount of disk space to be reclaimed by Offline Defrag...

By using the command eseutil /ms, we can calculate the exact amount of disk space that can reclaimed by doing the offline defrag.

Here are the steps:

1) Run eseutil /ms command from the bin directory on the dismounted database. It will always be run on the edb file.

2) The first section of the space report is the SLV SPACE DUMP. This reports on free space in the streaming database file (.stm).
TOTALS:
Free: 1528814
Reserved: 2238
Deleted: 228
Committed: 11888
Unknown: 0

There are 1528814 free pages in the .stm file, and each page is 4096 bytes in length. Therefore, there are 6,262,022,144 bytes of empty space in the file (1528814 x 4096).

3) As for the EDB file dump you'll see the following information in the last line in the column 'Available'
-------------------------------------------------------------------------------
3244272

The number at the lower right of the output (3244272) is the total of all free pages in the database. If you multiply this number by 4096, you will see that defragmenting this database will recover 12.3 gb of space.

4) Hence, based on the above example you will recover 12.3 GB + 6GB after you do the offline defrag.(this is including the STM also)

System Attendant Mailbox Missing: Users getting NDRs, Cant Move Mailboxes...

In this scenario, the users are getting NDRs that System Attendant cannot be reached... and when we try to move the mailbox to and from the server, the error says:
"The attempt to log on to the Microsoft Exchange Server computer has failed. The MAPI provider failed. Microsoft Exchange Server Information Store ID no: 8004011d-0512-00000000"

The application log has the following error messages:

Event ID : 9175
Raw Event ID : 9175
Record Nr. : 1167709
Category : MAPI Session
Source : MSExchangeAdmin
Type : Error
Message : The MAPI call 'OpenMsgStore' failed with the following error:
The attempt to log on to the Microsoft Exchange Server computer has failed.
The MAPI provider failed.
Microsoft Exchange Server Information Store
ID no: 8004011d-0512-00000000

These symptoms indicate that the ‘mailbox store’ that holds the System Attendant mailbox is down or that the SA mailbox is disconnected, but actually all the mailbox stores are up and running on the server.
There is only one mailbox store in an Exchange server that holds SA mailbox... but you cannot find this mailbox on any of the stores.
And when you verify the attributes of System Attendant using ADSIEdit under Microsoft System Attendant, it is found that homeMDB was ‘Not Set’

Recommended Plan:
=================

• Using ADSIEdit, browse to the location – Configuration – Microsoft Exchange - - Administrative Groups - - Servers – – Information Store -, on the right side you’ll see a list of mailbox stores, click on any one of them and copy the value of ‘Distinguished Name’ attribute
• Using ADSIEdit, browse to the location – Configuration – Microsoft Exchange - - Administrative Groups - - Servers – – Microsoft System Attendant, right click here and find the attribute ‘homeMDB’, paste the value that you copied earlier (From ‘Distinsguished Name’) here
• Restart ‘Microsoft Exchange System Attendant’ service
• After the exchange services come up, browse to the store whose DN value you copied earlier and find the System Attendant mailbox under ‘Mailboxes’ list, if you don’t find it run a ‘Cleanup Agent’

If you don’t see the SA mailbox in the ‘Mailboxes’ list on the store even after performing ‘Run Cleanup Agent’. Using ADSIEdit, once you get to the properties of the ‘Microsoft System Attendant’ you can note the value of the the attribute ‘mail’. This is essentially the primary SMTP address of the SA mailbox. You can send an email to this address, that should initialize the mailbox and you should see it under ‘Mailboxes’ tab in ESM.