Exchange Acquisition

The has taken over
Starting 5pm on Friday, all employees of must start using the email system of (citrix access to outlook) .
All existing mail in databases must be moved appropriate mailboxes on
You have been given a spreadsheet that has the old and new userid, names, email addresses on the system.

More information about the cutover at 5pm on Friday:
Incoming emails to will be intercepted by “Postfix SMTP routers”
A small list of email address will be allowed, the incoming email address recipient address will be translated to the appropriate address.
For Example: will be translated to
All others will be rejected.
As a side note to exchange savvy admins, the BigCompany’s exchange system does not recognize the as authoritative or internal.
In either case, all incoming email to accounts will get a reply from “Postfix SMTP” that says

“This recipient has been acquired, please contact the recipient for the appropriate email address. By default it is, you can try that.”
This email has been generated by Postfix SMTP relay of

Migration technique used: Exmerge. has about 50 Gigabyte of data.
The process to move existing mail and calendar data on the Exchange 2003 system is exmerge.

“Exmerge” comes with exchange 2003 and will export all mailbox data to a “pst” file.
Yes, all reoccurring appointments come over, all email, etc. It is all transported in the pst file.

On the old exchange server, create a folder called PassONE and PassTWO.
Run exmerge against all accounts, one or two days before cutover (which is 5pm on Friday).
You won’t be setting any date filter on this pass, which means everything, from as far back as the data goes to today.

I expect this data to be about 50Gig worth of pst files.
Then at 5pm, after incoming SMTP mx records are changed to the BigCompany, run exmerge again.
This time, set the Exmerge date filter to grab only the last two days of email.
Exmerge will be much faster than before.

Finally, copy the folders PassOne and PassTWO to the destination exchange 2007 server in the system.
PassOne was about 50 Gigabyte, and PassTWO was about 0.5 Gigabyte (500Meg).
I found a large amount of space on the same drive that database resides on, so it put those folders there.

Then I run the PowerShell command against the pst files.
In most cases, it will be the samid logon name from the old domain, but if the user got married and changed their names, it might have a slightly different name.
If you browse for the user in question using exmerge program, you can see what the exported pst file will be named.

Out of 400 uses, I had 10 I had to manually fix.
In short, you will have a file that looks like this, here are only 10 lines, one for each users.
The name of the pst file is typically the userid on the small business side, and the email address identifies the user on the BigCompany side.

Import-Mailbox -Identity -PSTFolderPath D:\PassONE\ACALKINS.PST
Import-Mailbox -Identity -PSTFolderPath D:\PassONE\ADICK.PST
Import-Mailbox -Identity -PSTFolderPath D:\PassONE\ADIECK.PST
Import-Mailbox -Identity -PSTFolderPath D:\PassONE\ADORNER.PST
Import-Mailbox -Identity -PSTFolderPath D:\PassONE\AEDWIN.PST
Import-Mailbox -Identity -PSTFolderPath D:\PassONE\AFISKIN.PST
Import-Mailbox -Identity -PSTFolderPath D:\PassONE\AGIESE.PST
Import-Mailbox -Identity -PSTFolderPath D:\PassONE\AGLANNER.PST
Import-Mailbox -Identity -PSTFolderPath D:\PassONE\AHARTMANN.PST
Import-Mailbox -Identity -PSTFolderPath D:\PassONE\AHOHN.PST

The nice thing about working with pst files is that duplicate messages are not created if you should import overlapping pst files, or the same file twice.
The other nice thing is its speed when specificing a date range.

Many mail migration tools take the same amount of time regardless of data range you are looking at.
Exmerge is very fast when you specify a short data range. Which makes it possible to perform a relatively short cutover.

This project was successful because all accounts at could be provisioned a head of time, and the pst files from PassOne can be applied. At cutover time a final pst export consisting of the last two days (PassTWO) is exported and then imported on the BigCompany accounts.

The downfall was that messages sent from users don’t get a reply (if you clicked reply in outlook and the message is going back to someone
That problem fades with time…. you typically reply within days to an email, after that, you typically don’t reply.


Author: Mike

owner of blog

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