Migrations to and from Exchange cover many scenarios and versions. The following answers do not apply to all migrations, so be sure to check which versions you are using and which sets of steps apply to your scenario. 

Enable Cross-Tenant EWS Access  

Version: Exchange 2010 only

To migrate with a single set of administrative credentials within an Exchange 2010 multi-tenant environment, create a new management role granting access.

To grant access to an administrative migration account called "MigrationWiz":

1. 1. Open the Exchange Management Shell.
   2. Enter the following commands:
      
      New-ManagementScope
-PartnerDelegatedTenantRestrictionFilter {Name -eq '*'}
-Name MigrationWizScope
New-ManagementRole
-Parent PartnerDelegatedTenantManagement
-Name MigrationWizRole
New-ManagementRoleAssignment -Role MigrationWizRole -User MigrationWiz -CustomConfigWriteScope MigrationWizScope

Verifying OWA URL

When setting up Exchange as an endpoint, enter either the Outlook Web Access (OWA) URL or the Exchange Web Services (EWS) URL.

There are some instances in which the login page for OWA is different than the actual OWA URL for the mailbox, as you may get redirected to a different server after logging in. To determine the true OWA URL, perform the following:

Example URLs for OWA:

• • https://www.mining88.com
  • https://www.mining88.com/owa
  • https://www.mining88.com:443
  • https://50.249.230.12/owa

Another method for determining the OWA URL is to use the "whatismyipaddress" website to determine the company public IP address, and then add /owa to the end of it.

Now that your OWA URL has been determined, we need to ensure that the username and password combination work. The username and password that you use to log in to OWA is the exact same username and password that you should be entering into MigrationWiz. To determine if your username and password is working:

1. Close all browser instances. This ensures that all session state browser cache is flushed.
2. Open a new browser instance.
3. Navigate to the same OWA login page as determined by Step 5 above.
4. Log in to OWA. Pay special attention to the login name, i.e.​,:
• Email address means "user@example.com" format.
• Domain\user name means "example\user" format.
• User name means "user" format.
5. Once you see the inbox, you have successfully logged into OWA. Enter the exact same username and password used into MigrationWiz.

Increasing Size & Data

Increasing Exchange message size

Version: Exchange 2007-2019

This is a two-step process. The reason for this is that if the message size limits of Exchange are increased, the IIS limits will also have to be increased to allow increased payloads. There are other non-standard settings that can also cause size restrictions for the IIS or EWS connections, but we are unable to troubleshoot or identify specific environment restrictions outside of these settings.

Increase the Message Size Limits of Exchange

To display current message size limits:​

1. Open the Exchange Management Shell.
2. Enter the following commands:

Get-TransportConfig | Format-List -Property MaxReceiveSize, MaxSendSize
Get-SendConnector | Format-List -Property Identity, MaxMessageSize
Get-ReceiveConnector | Format-List -Property Identity, MaxMessageSize
Get-MailBox | Format-List -Property PrimarySmtpAddress, MaxSendSize, MaxReceiveSize

To increase message size limits on the Exchange Server:​

1. Open the Exchange Management Shell.
2. ​Enter the following commands:​

​Set-TransportConfig -MaxReceiveSize 150MB -MaxSendSize 150MB
Get-SendConnector | Set-SendConnector -MaxMessageSize 150MB
Get-ReceiveConnector | Set-ReceiveConnector -MaxMessageSize 150MB
Get-Mailbox | Set-Mailbox -MaxSendSize 150MB -MaxReceiveSize 150MB

Increase IIS Limits to Allow Accepting Payloads

There are three limits that should be increased in IIS:

• maxRequestLength
• maxAllowedContentLength
• maxReceivedMessageSize

Follow these steps to increase the Exchange message size limits on your client access server:

1. OpenWindows Explorer.
2. Navigate to %ExchangeInstallPath%FrontEnd\HttpProxy\ews\
3. Open the file Web.Config in a text editor, such as Notepad.
4. Find the XML tag starting with for each change.
5. Change the existing value to maxRequestLength="200000"​ -- this occurs in one place in the Web.Config file.
6. Change the existing values to maxAllowedContentLength="200000000"​ -- this occurs one place in the Web.Config file.
7. Change the existing values to maxReceivedMessageSize="200000000" -- this entry occurs up to 12 times. This needs to be changed for each Authentication method.
   For example:
   <httpsTransport maxReceivedMessageSize="200000000" authenticationScheme="Anonymous" maxBufferSize="81920" transferMode="Streamed" />
   <httpsTransport maxReceivedMessageSize="200000000" authenticationScheme="Basic" maxBufferSize="81920" transferMode="Streamed" />
   etc.
8. If you are running IIS7 and Windows 2008, it may be necessary to increase WCF settings.
9. Save the file.
10. IIS Reset is not needed, web.config changes are picked up by the next conne​ction.

​​Follow these steps to increase the Exchange message size limits on your mailbox server:

1. OpenWindows Explorer.
2. Navigate to %ExchangeInstallPath%ClientAccess\exchweb\ews\
3. Open the file Web.Config in a text editor, such as Notepad.
4. Find the XML tag starting with for each change.
5. Change the existing value to maxRequestLength="200000"​ -- this occurs in one place in the Web.Config file.
6. Change the existing values to maxAllowedContentLength="200000000"​ -- this occurs one place in the Web.Config file.
7. Change the existing values to maxReceivedMessageSize="200000000" -- this entry occurs up to 12 times. This needs to be changed for each Authentication method.
8. If you are running IIS7 and Windows 2008, it may be necessary to increase WCF settings.
9. Save the file.
10. IIS Reset is not needed, web.config changes are picked up by the next conne​ction.

Increase the Maximum Received Message Size

If you are running IIS7 and Windows 2008, you may need to increase WCF settings:

1. Open Windows Explorer.
2. Navigate to C:\Program Files\Microsoft\Exchange Server\ClientAccess\exchweb\ews
3. Open the file Web.Config in a text editor like Notepad.
4. Find all XML tags starting with maxReceivedMessageSize=
5. Change existing values to maxReceivedMessageSize="104857600"
6. Save the file.
7. Open a Command Prompt (cmd.exe).
8. Type: cd %windir%\system32\inetsrv
9. Type: appcmd.exe set config "Default Web Site/ews" -section:requestFiltering -requestLimits.maxAllowedContentLength:104857600
10. Run: iisreset

Increase MAPI property limits

Some Exchange servers that have been in commissi​on for years may hit MAPI named property limits. These limits are reached when we attempt to retrieve more properties than the server is configured for. You will know if your server reaches these limits as an event similar to the following is logged:

Event Type: Error Event Source: MSExchangeIS Event Category: General Event ID: 9667 Date: 6/11/2010 Time: 4:56:13 PM User: N/A Computer: SERVERNAME Description: Failed to create a new named property for database "First Storage Group\Mailbox Store (SERVERNAME)" because the number of named properties reached the quota limit (8192). User attempting to create the named property: "SYSTEM" Named property GUID: 00062002-0000-0000-c000-000000000046 Named property name/id: "33377"

To increase the number of MAPI named properties:

1. Start the Registry Editor on the mailbox server.
2. Locate the following registry key:
   • HKLM\SYSTEM\CurrentControlSet\Services\MSExchangeIS\<ServerName>\<Private-GUID>
3. Set the following DWORD values or create new values if they do not exist.
   • NonMAPI Named Props Quota == 00007fff
   • Named Props Quota == 00007fff

You may either wait approximately 30 minutes for these values to take effect automatically, or reboot the server to take effect immediately.

These instructions have also been documented on the Microsoft website.

Maximum Accepted Content Length

You may increase the maximum accepted content length by following these directions:

1. Open Windows Explorer.
2. Navigate to C:\Program Files\Microsoft\Exchange Server\ClientAccess\exchweb\ews
3. Open the file  Web.Config  in a text editor such as Notepad.
4. Go to the end of the file.
5. Insert or edit the following XML code before the </configuration> tag:
   
   <system.webServer>
<security>
<requestFiltering>
<requestLimits maxAllowedContentLength="104857600" />
</requestFiltering>
</security>
</system.webServer>

If XML code is already present in the Web.Config file, edit it to match what is shown above.

Sample Web.Config before changes:

<configuration>
<system.web>
...
...
</system.web>
</configuration>

Sample Web.Config after changes:

<configuration>
<system.web>
...
...
</system.web>
<system.webServer>
<security>
<requestFiltering>
<requestLimits maxAllowedContentLength="104857600" />
</requestFiltering>
</security>
</system.webServer>
</configuration>

Increased Maximum Accepted Request Length

Version: Exchange 2007

Exchange Server 2007 has a default maximum accepted request length of 13MB. You may increase the maximum accepted request length by performing the following:

1. Open Windows Explorer. 
2. Navigate to C:\Program Files\Microsoft\Exchange Server\ClientAccess\exchweb\ews
3. Open the file Web.Config in a text editor such as Notepad.
4. Find the XML tag starting with maxRequestLength= 
5. Change the existing value to maxRequestLength="102400"
6. Save the file.

A value of 102400 represents 100 MBs in kilobytes.

Sample Web.Config before changes:

<configuration>
<system.web>
...
...
<httpRuntime maxRequestLength="13280" />
</system.web>
</configuration>

Sample Web.Config after changes:

<configuration>
<system.web>
...
...
<httpRuntime maxRequestLength="102400" />
</system.web>
</configuration>

Increase Allowed Number of Concurrent Connections

To display current allowed number of concurrent connections per user:

1. Open the Exchange Management Shell.
2. Enter the following command and press Enter: 
   
   Get-ThrottlingPolicy | Format-List -Property Identity, EWSMaxConcurrency

To increase allowed number of concurrent connections per user on your Exchange Server 2010 machine:

1. Open the Exchange Management Shell.
2. Enter the following command and press Enter:
   
   Set-ThrottlingPolicy -Identity DefaultThrottlingPolicy* -EWSMaxConcurrency $null

Calendar Event Ownership

MigrationWiz looks at the Source email address to know who the owner of an event is. If your calendar events are being migrated but you are not being shown as the owner of the event, confirm that the Source email address matches the email address of the creator of the event at the Source.

Set Time Zone for Mailbox Migration Destinations

Under some circumstances, mailbox migrations to an Exchange environment will show the incorrect time for calendar events. This happens when the time zone on the Destination is incorrect. The cause of involves synchronization of time values when calendar items migrate.

To ensure that this error does not affect your migrations, ensure you have set the correct time zone at the migration Destinations.

For more information about Google calendar time settings, see Use Google Calendar in different time zones.

Define Reference UTX/GMT Time Zone in Exchange

Import the attached registry file to ensure the reference UTC/GMT time zone is defined on your client access Exchange Server(s):

1. Download the attached file and save to disk.
2. Double-click on the file and import into the registry.
3. Execute iisreset (restarts IIS, allowing Exchange Web Services to detect the new time zone)​​.