1. BitTitan Help Center
  2. Perform a Migration
  3. Microsoft Migrations
  4. Exchange Online Mailbox Migrations using Graph API
  5. Mailbox Migrations Guides using Graph
  6. Exchange and Microsoft 365 as Source

Microsoft 365 using Graph API to (Hosted and On-Premises) Exchange (2013+) Migration Guide

Notes

  • Although present in the UI, BYO App using Client Certificate is currently unavailable. We are working on a resolution for this issue at this time.
  • GoDaddy-Hosted Office 365 is currently not supported with the Graph Endpoints at this time.

This is the complete onboarding task flow for migrating mailboxes from Microsoft 365 using Graph API to Hosted Exchange or On-Premises Exchange, version 2013+.

MigrationWiz

MigrationWiz is a migration tool, not a syncing tool. If changes are made at the source after migration, they will not sync to the destination, nor will changes made at the destination sync to the source. We do not have “live” monitoring of changes (as with a sync agent) and we cannot handle scenarios such as conflict resolution without user interaction.

First time?

This migration guide contains the necessary steps to perform the actual migration, but there are many steps to preparing for migration. If this is your first time performing a migration, we have created a Migration Planning & Strategy Guide to walk you through planning, set-up, and general migration best practices.

Licensing

We recommend that you purchase User Migration Bundle licenses for this migration scenario. User Migration Bundle licenses allow the performance of multiple migrations with a single license. For questions on licensing, visit Which Migration License Do I Need?.

To use your license by following the next steps:

  1. Review Considerations.
  2. Purchase Licenses.
  3. Create a Customer.
  4. Apply Licenses.
ConsiderationsPurchase LicensesCreate a CustomerApply Licenses

Licenses are released once payment has been received:

  • Licenses are available immediately upon payment if you purchase via credit card.
  • If you purchase via wire transfer (100+ licenses), the licenses will be available once payment is received and accepted.
  • We do not accept purchase orders because of processing overhead.

In both cases, you will be notified by email that payment has been accepted and licenses are available in your account upon notification.

For more information on licensing, including coupon redemption and other licensing types, see our Which Migration License Do I Need? guide.

Limitations

  • Due to Microsoft limitations, using Delegate Permissions with Graph API is not supported at this time. Only Application Permissions can be used.
  • Pinned/Flagged Emails are migrated but not Pinned/Flagged in the destination environment.
  • Threading (email messages that belong to the same conversation) is not supported and will require Manual implementation. 
  • Delegate-level calendar access isn't supported by Microsoft Graph. It's automatically downgraded to Free/Busy-only.
  • Archive Mailbox as a destination is currently not supported. Support for this option is planned for a future release.

Migrated Items

Please click the bars below to check the migrated and non-migrated items. We are constantly working to create a better migration experience for you so these items may change over time.

Which items are migrated?
  • Inbox
  • Folders
  • Email
  • Contacts
  • Calendars
  • Tasks
  • Journals
  • Notes
  • Post (when the destination is Exchange or Microsoft 365)

  • Automatic Replies (Out of Office Messages for Exchange 2013 and 2016 only)

    Important

    It is recommended that only Automatic Replies be migrated in the last migration pass for the user. 

  • Personal Folder and Calendar Permissions (Exchange 2013 and 2016 only)
Which items are not migrated?

Never Migrated

  • Safe Sender/Block Lists
  • Calendar acceptance status emails

  • Rules

    Important

    Although you can see the Rules as an option to select, they are not supported due to the high volume of rules that are not accepted by Hosted Exchange/Exchange On-Premises when the Source is Exchange Online. Rules will have to be created manually in the destination Mailboxes. 

Groups

  • Notebooks
  • For Group documents: anything not in a document library (See SharePoint)

For additional features and limitations please visit MigrationWiz: Migrated and Not Migrated Items.

Prepare the Source Environment

Modern Authentication Requirements

The KBs listed in the Exchange Online Authentication options using Graph API section will help you configure the source tenant when using Microsoft 365 with the Microsoft Graph API. A Global Administrator account is required to consent to the BT app or create and consent to the BYO app, since the Entra app's permission types require global admin approval.

Export the User List to a CSV File

This can be used when bulk-adding users to your MigrationWiz project later. You can copy and paste the user list into the Source and Destination Email columns within your MigrationWiz project dashboard under Add > Bulk Add.

To export the user list:

  1. Go to the Microsoft 365 admin portal.
  2. Click Users.
  3. Click Active Users.
  4. Click Export Users.
  5. Click Continue.

Be sure to save the CSV somewhere you can access it for upload later in the migration.

Disable Throttling Against the Admin Account

The Exchange Server has very low throttling policy limits. We recommend disabling the throttling limits during the migration. This is only relevant if throttling policies are enabled in the Exchange environment. If you are creating or applying a throttling policy on Exchange, you will need to use delegation for this endpoint.

There are two options for this process. Choose which one works for you, and then expand the relevant set of instructions below. 

Option 1Option 2

Disable throttling against only the migrating account (if not using impersonation). This way, the admin account can migrate at a faster rate because it is not subjected to any throttling.

Use this option if you are not using impersonation during the migration, but instead using delegation. If migrating using admin credentials, it is only necessary to disable throttling against the admin account, rather than all users. If migrating mailboxes using administrative credentials at the Source, but not using impersonation, we recommend disabling throttling limits on this administrative account to improve the speed of migration.

We recommend you Set Up an Exchange Administrator Account and disable policy enforcement for this account.

Read Message rate limits and throttling before you execute the scripts below.

Admin Account: Exchange 2013+

To disable all throttling parameters for an admin account called "MigrationWiz":

  1. Open the Exchange Management Shell.

  2. Type the following command and press Enter.

    New-ThrottlingPolicy MigrationWizPolicy

  3. Type the following command and press Enter.

    Set-ThrottlingPolicy MigrationWizPolicy -RCAMaxConcurrency Unlimited -EWSMaxConcurrency Unlimited -EWSMaxSubscriptions Unlimited -CPAMaxConcurrency Unlimited -EwsCutoffBalance Unlimited -EwsMaxBurst Unlimited -EwsRechargeRate Unlimited

  4. Type the following command and press Enter.

    Set-Mailbox "MigrationWiz" -ThrottlingPolicy MigrationWizPolicy

Option 2: Disable throttling against all user accounts (if migrating using an admin account and using impersonation). This way the admin account can migrate at a faster rate because it impersonates user accounts, which are not subjected to throttling.

If migrating mailboxes using administrative credentials at the Source, and using impersonation, disabling throttling limits on all mailboxes will improve the speed of migration, but it is a security risk. The throttling limits are working together to protect an Exchange server from being overwhelmed by accepting and delivering messages.

Read Message rate limits and throttling before you execute the scripts below.

All Mailboxes: Exchange 2013+

To disable all throttling parameters for all mailboxes:

  1. Open the Exchange Management Shell.

  2. Type the following command and press Enter.

    New-ThrottlingPolicy MigrationWizPolicy

  3. Type the following command and press Enter.

    Set-ThrottlingPolicy MigrationWizPolicy -RCAMaxConcurrency Unlimited -EWSMaxConcurrency Unlimited -EWSMaxSubscriptions Unlimited -CPAMaxConcurrency Unlimited -EwsCutoffBalance Unlimited -EwsMaxBurst Unlimited -EwsRechargeRate Unlimited

  4. Enter the following command and press Enter. 

    Get-Mailbox | Set-Mailbox -ThrottlingPolicy MigrationWizPolicy

The steps above will remove throttling policies against all user accounts at your Destination. You still need to enable impersonation within your MigrationWiz project, so that the admin account can impersonate the user accounts during migrations, and so that the migrations use the bandwidth available to the individual user accounts, rather than just the bandwidth available to the admin account. 

Prepare the Destination Environment

Set up the User Accounts

You can use the CSV acquired in the previous step as an easy reference point for creating these accounts. 

Create Admin Account

Create an admin account for migration that has full access permissions to all mailboxes. Any user account that is a part of the domain administrator, schema administrator, or enterprise administrator groups will not have any administrative rights to mailboxes, no matter how many permissions are granted. A security default of Exchange Server is to explicitly deny any user that is a member of these groups. This is why we recommend creating a new user account specific for migration.

  1. Open the Exchange Admin Console.
  2. Click New and select User Mailbox.
  3. Click New User.
  4. Enter "MigrationWiz" as the Display name.
  5. Enter "MigrationWiz" as the Name.
  6. Enter "MigrationWiz" as the User logon name.
  7. Enter the service account password. 
  8. Select Save.

To grant the account access, perform the following steps while in the Exchange Server machine. The command needs to be applied each time a new mailbox is created since permissions are set directly on each mailbox. The administrative account will not have access until the permissions are applied.

  1. Open the Exchange Management Shell.
  2. Enter the following command:
    Get-Mailbox -ResultSize Unlimited | Add-MailboxPermission -AccessRights FullAccess -User MigrationWizChange the -User account to match the name of the admin account that was set up for migration. This username is the Administrative Username that needs to be entered under project source or destination settings, within MigrationWiz, when check marking the box labeled: Use Administrative Login.

Optional: Large Messages

If you want to be able to migrate messages with attachments larger than 10MB, the following limits need to be increased:

Increase Message Size Limits

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. Other non-standard settings 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.

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

Three limits should be increased in IIS:

  • maxRequestLength
  • maxAllowedContentLength
  • maxReceivedMessageSize

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

  1. Open Windows 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 each change.
  5. Change the existing value to maxRequestLength="200000" -- this occurs in one place on the Web.Config file.
  6. Change the existing values to maxAllowedContentLength="200000000" -- this occurs in one place on 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 connection.

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

  1. Open Windows 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 each change.
  5. Change the existing value to maxRequestLength="200000" -- this occurs in one place on the Web.Config file.
  6. Change the existing values to maxAllowedContentLength="200000000" -- this occurs in one place on 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 connection.

Increase 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, then edit it to match what is shown above.

Web.Config before changes Web.Config after changes
<configuration>
<system.web>
...
...
</system.web>
</configuration>
Increase 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.

MigrationWiz Steps

Create a Mailbox Migration Project

Mailbox projects are used to migrate the contents of the primary user mailbox from the previous environment to the new environment. Most mailbox migrations can migrate email, calendars, and contacts.

  1. Click the Go to My Projects button.
  2. Click the Create Project button.

  3. Select the Mailbox Project.

    Important

    For mailbox migrations, use the migration service credentials to access mailboxes. In most migration scenarios, this account must have full access rights to the Source mailboxes.

  4. Click Next Step.
  5. Enter a Project name and select a Customer.
  6. Click Next Step.
  7. Select endpoints or follow the steps below to create new endpoints.
  8. Click Save Project.

 

Mailbox Migration Settings: Every setting on the project is applied to all mailboxes associated with that project. For settings that are represented as checkboxes, only selected settings are applied to the project. Not selecting a checkbox does not disable a selected setting inherited from the project.

Endpoints

Service Account Password

Before migrating, ensure that the service account password does not contain any commas. If it does, update the password before starting the migration process.

Endpoints are created through MigrationWiz. If you select an existing endpoint from the dropdown, it will only show ten endpoints. If you have more than ten, you may need to search it.

Consider that endpoint search is case and character-specific. For example, Cust0mer will not show up if the search is customer. We recommend keeping a list of endpoints you have created, along with any unique spellings or capitalization you may have used.

Create your Endpoints

Please review the following tabs to create your destination and source endpoints.

Source EndpointDestination Endpoint

Create your source endpoint by following the next steps:

  1. Click New.
  2. Name the endpoint. It is recommended that the endpoint's name be unique for the project.
  3. Select Microsoft 365 Graph API for the endpoint type and click Add.
  4. In the Permissions section, Application Permissions are selected by default (Delegated Permissions are not supported at this time).
  5. Complete the Migration Service Account and the Tenant ID.
  6. Click Save Project.

Add Users

Add the user accounts that will be migrated to the project. This may be done in several ways, depending on the size of the project. Steps for each option are in the accordion below, simply click to show the option you select and follow the guidance there.

Small Migrations

For small migrations, it is easy to add users one at a time using Quick Add. The steps for this are below. 

Larger Migrations

For larger migrations, we recommend either using the Autodiscover or Bulk Add option.

Quick Add

This option allows you to add items one at a time. To do so, you only have to provide an email address if you entered administrative credentials when setting up the project. If you did not, enter the following user information:

  • An email address
  • Login name
  • Password
  • Mailbox status
Bulk Add

Bulk Add uses a CSV containing the source and destination email addresses for the users to add the users to the project. If migrating only a specific group from a tenant, we recommend using the Bulk Add option.

MigrationWiz allows you to bulk import mailboxes into the system.

To import one or more mailboxes:

  1. Sign in to your MigrationWiz account.
  2. Select the Project for which you want to perform the bulk import.
  3. Click Add.
  4. Click Bulk Add.

  5. Follow the instructions on the page.

    Important

    After adding new users to the Bulk Add Items page, make sure to select the radio button All newly detected mailboxes will be migrated as shown below before clicking on the green Save button)


    New Bulk Add Requirement.png
     

Autodiscover

​Autodiscover process within MigrationWiz can be used to discover items from the Source environment so that they can be imported into your projects. This can then be edited in the project to remove users not being migrated. All users are added with the source and destination email addresses set to match the source email.

This can be changed by using the Change Domain Name button at the top of the project page. If the usernames are changing during the migration, we recommend using the Bulk Add option.

There are a few requirements for this to work:

  • The Source has to be Exchange 2007 or later, or Microsoft 365, or G Suite. If you are using Autodiscover from G Suite, all G Suite domains must be added to the list of domains in the Endpoint.
  • The endpoint on the Source needs to use admin credentials.
  • For mailbox migration projects, the admin account that is specified within the Source endpoint needs to have a mailbox associated with it.
  • The admin mailbox must be listed in the public Global Address List (GAL).
  • The migration project type needs to be a Mailbox migration. For the exact steps to be followed during your migration, refer to the relevant Migration Guide. All Migration Guides can be found on the Help Center site.

One additional item to note here is that there is no way to restrict the IP addresses that the connection will come from.  This means that the steps outlined in our IP Lockdown guide will not apply here.  If your environment requires that any IP addresses be whitelisted, it is recommended that items be added to your project using one of the other available options.

Autodiscover of items will not work while using Modern Authentication

Autodiscovery exposes the following items:

  • For mailbox migration, autodiscovery will list all mailboxes at the Source.

Steps to Run Autodiscover

  1. Navigate to the project you want to import users into.
  2. Ensure that you have created an endpoint for the source project.
  3. Once in the project, on the top navigation bar, click on the Add drop-down, then select Autodiscover Items. This will begin the Autodiscover process.
  4. Once discovered, click on the Import button, to import the items into your MigrationWiz project.

Advanced Options

Support Tab

  • InitializationTimeout=8 This increases the initialization timeout window to eight hours. This value is in hours, up to a maximum of 100 hours. Values above 100 are in milliseconds. For example:​
    • InitializationTimeout=2 will increase the timeout to 2 hours.
    • InitializationTimeout=8 will increase the timeout to 8 hours.
    • InitializationTimeout=14400000 will increase the timeout to 4 hours.
    • InitializationTimeout=21600000 will increase the timeout to 6 hours.

Bulk Load

To upload a large list of Advanced Support options, see the Bulk Load - Advanced Options when Migrating Mailbox projects using Graph API for additional guidance.

Run Verify Credentials

You may verify the credentials of items in MigrationWiz without migrating data or consuming any licenses.

  1. Open the Project containing items you wish to validate.
  2. Select the items you wish to validate.
  3. Click the Start button in your dashboard.
  4. Select Verify Credentials from the drop-down list.

Once complete, the results of the verification will be shown in the Status section.​

Notify Users

Notify users that a migration is occurring. Send an email to all users telling them the time and date of the migration.

Run Migration

Pre-Stage pass

  1. Select the users you wish to migrate.
  2. Click the Start button from the top.
  3. Select Pre-Stage Migration.
  4. Uncheck the box named Automatic Replies (This option will be removed from the Pre-Stage pass at a later date)
  5. Under the Migration Scheduling section, from the drop-down list, select 90 days ago.
  6. Click Start Migration.

MX Record Cutover

Change over MX records on the DNS provider's portal. Also, include the AutoDiscover (CName) setting.

Send an email to end users to let them know what to expect for their Outlook profile reconfiguration. If using DeploymentPro, refer to Sample email to send to users before their Outlook profile is reconfigured for some sample text and screenshots that can be included in this email.

Full (Delta) pass

  1. Select the users.
  2. Click the Start button from the top.

  3. Select Full Migration. 

    Important

    It is recommended that only Automatic Replies be migrated in the last migration pass for the user. 

  4. Click Start Migration.

Run Retry Errors

Look through the user list and click any red "failed migration" errors. Review the information and act accordingly.

If problems persist, contact Support.

Related Topics

Was this article helpful?
0 out of 0 found this helpful

Articles in this section