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Cross Forrest Mailbox migration

Hi Experts,

we have a project to do with migrating mailboxes from EXCH-A to EXCH-B.
Both exchange servers belong to different forrests.

Do you have a manual or link for that ?

The EXCH-A is version 2016
The EXCH-B is version 2013.
Is this possible ?
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MASEE Solution Guide - Technical Dept Head
SILVER EXPERT
Most Valuable Expert 2017

Commented:
It will be easy to use 3rd party softwares and migrate from forest A Exchange to Forest B exchange.

Can you explain what your client's requirement?
Maybe we can propose something better.
Eprs_AdminSystem Architect

Author

Commented:
We will have to migrate thr mailboxes from forest A to forest B.
The users still in forest A but the mailbox is in forest B.

Can we use new-migrationbatch for that ?
Because the mailbox in the source is on EX2016 and the traget exchange is EX2013.

What do you think ?
MASEE Solution Guide - Technical Dept Head
SILVER EXPERT
Most Valuable Expert 2017

Commented:
You need to have two way trust between forests and add the Target Exchange organization .
Server engineer
BRONZE EXPERT
Commented:
From EXCH-A to EXCH-B. ( NOT POSSIBLE)

The EXCH-A is version 2016
The EXCH-B is version 2013.

You are migrating from 2016 which is higher version to lower version 2013. NOT POSSIBLE only lower 2013 to higher 2016.

Take out PST and create new mailboxes on 2016 forest B exchange 2013.
Saif ShaikhServer engineer
BRONZE EXPERT

Commented:
Taking out PST also take out the X500 address of mailboxes and add them back in the new mailboxes on migrated forest..
Jason CrawfordTransport Ninja
BRONZE EXPERT

Commented:
You're going to have to upgrade your 2013 server to 2016.  Unless you want to test your upper limit of frustration don't try to migrate using .pst files.  Since the mailboxes all live in a separate forest there is no need for legacyExchangeDn / X500 addresses either.  The challenge you'll face is password and SID history both of which are accounted for in the ADMT (Active Directory Migration Tool); however, it's not really appropriate in this instance since the AD users and mailboxes are already established in the target.  If flipping the migration from 2013 to 2016 isn't an option you'll most likely want to shell out the $9.99 per mailbox for Migration Wiz, otherwise the next best option I can think of is introducing a third forest (similar to a resource forest) to facilitate the unique position you're in.  I'm happy to help if you need a hand.
Eprs_AdminSystem Architect

Author

Commented:
Hi Jason,

can you confirm, I have to upgrade the EX2013 ?

Now when I try to move the mailboxes to the new forrest with GUI, I get this error:

MapiExceptionCorruptData

Any ideas ?
Eprs_AdminSystem Architect

Author

Commented:
what does it mean ?

MapiExceptionCorruptData
Eprs_AdminSystem Architect

Author

Commented:
do I need to trust some certificates ??
Saif ShaikhServer engineer
BRONZE EXPERT

Commented:
Have you tried below command:

New-moverequest -identity "" -BadItemLimit 100 -AcceptLargeDataLoss

Modify the baditemlimit as per your needs.
Eprs_AdminSystem Architect

Author

Commented:
Hi Saif,

it hasnt to do with the dataloss or baditemlimits.
I get SSL errors.
Saif ShaikhServer engineer
BRONZE EXPERT

Commented:
Provide the complete error information. Incomplete information will not lead to solution.

You can remove or colour the sensitive information in the error liek domain name and all.
Eprs_AdminSystem Architect

Author

Commented:
I hope I can get this info nect week
Eprs_AdminSystem Architect

Author

Commented:
Here is the full error:
MapiExceptionCorruptData.png
Saif ShaikhServer engineer
BRONZE EXPERT

Commented:
1. Have you tried moving one or two mailboxes by themselves?

Can you move a single small mailbox over?

If yes, it may be a matter of mailbox size and this post may help:

http://social.technet.microsoft.com/Forums/en-US/exchangesvrmigration/thread/279bac54-f7bd-4d5e-884e-6c8701db13cc



2. Try modifying MSExchangeMailboxReplication.exe.config on the target CA server as follows:-

              binding name="MrsProxyClientBinding"
                 receiveTimeout="00:00:50"
                 sendTimeout="00:00:50">
          <reliableSession ordered="true" />
          <textMessageEncoding>
            <readerQuotas maxArrayLength="3048576"
                          maxStringContentLength="3048576" />
          </textMessageEncoding>
          <httpsTransport authenticationScheme="Negotiate"
                          maxReceivedMessageSize="3048576"
                          allowCookies="true" />
Eprs_AdminSystem Architect

Author

Commented:
I have tested several different mailboxes, always same error.

ok I will check next week.
Eprs_AdminSystem Architect

Author

Commented:
Hi All,

I have upgraded now to Exchange version 2016.
Now on both sides I have version 2016.

What kind of config is needed to migrate from Forest A to Forest B ?
Eprs_AdminSystem Architect

Author

Commented:
Thanks Saif,

after the exchange Upgrade to 2016 on site A, I was able to migrate all mailboxes.
Saif ShaikhServer engineer
BRONZE EXPERT

Commented:
You are most welcome...Glad to hear your issue was resolved.

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