G Suite (IMAP) to Office 365 Migration Guide

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.

To discover what items are moved with MigrationWiz in this scenario, and which items will not be moved, see Moved Items. Note that these items will vary by source and destination, so check the proper environment listings carefully.

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.

 Important: Migrating from a G Suite/Gmail endpoint requires an administrator email address which matches the end user domain.


Preparing the Source

Recommended Actions

The following sections are recommended to ensure that the migration of all data is possible and to prevent failures.

Set up API scopes with OAuth

BitTitan products use OAuth 2.0 to authenticate to G Suite  and utilize the G Suite (IMAP) endpoint in MigrationWiz. This is applicable to both mailbox and document migration projects. In order to obtain access to your G Suite data, it is necessary to add specifically allowed API scopes to the MigrationWiz project.

  • These steps must be followed whenever there is a migration project either to or from G Suite that will utilize the G Suite (IMAP) endpoint. For instructions on using the Gmail API endpoint, see  MigrationWiz - Mailbox Migration - Set up Google API for migrating mailboxes.
  • Enabling access is required for both G Suite mailbox and Google Drive document migration projects.
  • Mailbox migration projects require that a G Suite administrator grant access to the BitTitan client ID and scopes listed in this article.
  • Document migration projects require that a G Suite Super administrator grant access to the BitTitan client ID and scopes listed in this article and enable the API access. The steps to do this are included at the bottom of this article.

Steps in the G Suite Admin Console

Complete these steps to grant BitTitan client ID access to the appropriate scopes:

  1. Go to https://admin.google.com and authenticate as a Super Administrator.
  2. Click Security.
    Note: If you do not see the security icon on your admin console home page, you do not have the necessary rights on your account to make these changes. Request Super Administrator access from the customer to implement these changes.
  3. Click Advanced settings.
    Note: Google limits accessing and changing this setting to only G Suite Super Administrator accounts.
  4. You will now have one of two options, depending on whether your tenant has been updated to the new Google API or not. 

Old Google Tenant:

  • Go to the G Suite admin page at google.com
  • Click on Security
  • Click on Advanced Settings
  • Click Manage API Client Access.

OR If your account shows the latest UI updates from Google, as shown below:mceclip1.png

  • Go to the G Suite admin page at google.com
  • Click on Security
  • Click Advanced Settings
  • Under ‘Domain-wide delegation’, click Manage domain-wide delegation
  • On the Manage domain-wide delegation page, click Add new
  2. Click Add New.
  3. Enter 113321175602709078332 into the Client ID field. 
  4. Enter one of the following groups of scopes into the OAuth Scopes (comma-delimited) field, depending on whether G Suite is the Source or Destination.

    • G Suite as the Source (read-only scopes):
      https://mail.google.com/, https://www.google.com/m8/feeds, https://www.googleapis.com/auth/contacts.readonly, https://www.googleapis.com/auth/calendar.readonly, https://www.googleapis.com/auth/admin.directory.group.readonly, https://www.googleapis.com/auth/admin.directory.user.readonly, https://www.googleapis.com/auth/drive, https://sites.google.com/feeds/, https://www.googleapis.com/auth/gmail.settings.sharing, https://www.googleapis.com/auth/gmail.settings.basic
  5. Click Authorize.
    Note: The client name is 113321175602709078332 (make sure there are no leading or trailing spaces, as this may cause the error "URL ends with an invalid top-level domain name."). This will grant BitTitan products access to the appropriate scopes.


Enable IMAP Access

Ensure IMAP access is enabled for all users. For details on how to check this, refer to the Google support article here.

Enable Folder Size Limits

  1. Ensure the folder size limits on IMAP folders have been removed for all users. For each user:
  2. Click the gear icon
  3. Click Settings
  4. Select Forwarding and POP/IMAP tab
  5. Select Folder Size Limits
  6. Select the radio button for Do not limit the number of messages in an IMAP folder (default).

Note: This is an end user setting, which can only be set on a per-user basis. Therefore, we recommend that you send instructions to your end users to check this setting. Expand the following section for sample communication and instructions:

Sample communication to end users.

Action Required - Due Date XX/XX/XX We are preparing to migrate your environment. To ensure a seamless migration, certain end user settings must be verified. Follow the directions below to remove the folder limits on your account migration. Failure to do so in a timely manner may result in lost items. G Suite has a setting that can limit the number of messages in an IMAP folder. If this is configured, this will restrict MigrationWiz so that it can only retrieve and migrate that number of messages from each folder.

  1. Log in to your Gmail account.
  2. Click on the gear icon in the upper right-hand side of the window, and choose Settings.
  3. Click on the Forwarding and POP/IMAP tab.
  4. Under the IMAP Access heading, look for Folder Size Limits.
  5. Ensure that Do not limit the number of messages in an IMAP folder (default) is selected.

 Note: To further clarify the implications of this setting: If the limit has been set (e.g., to 1,000 as per the default suggestion), then if folders contain more than 1000 items, they will be truncated at 1000 items. This means that MigrationWiz will only be able to migrate 1000 emails from each folder. Thank you for your assistance. If you have any questions or concerns, please contact [Help Desk].

Export mailboxes to CSV file(s)

From the Google Admin portal:

  1. Click Users
  2. Click ⁝ (3 vertical dots)
  3. Download Users
  4. Download All Users
  5. Click OK
  6. Save

Preparing the Destination

Create Administrator Account

Create a Global Administrator or a delegated admin with full access rights or permissions account in Office 365 to be used for migration or use the Global Administrator or delegated admin with full access rights or permissions account for the tenant. In order to have administrative permissions to migrate mailbox data, grant the account permissions on each mailbox.


  • Having administrative access to the Microsoft Office 365 control panel to manage users does not mean the same account has permissions to access all mailboxes for migration.
  • Having delegated admin access to accounts does not provide enough access.

Enabling an administrative account the ability to access Office 365 user mailboxes can be performed by adding the Impersonation role or Full Access mailbox permissions.  The below steps will explain how to configure the permissions access for both options.


To enable the admin account to impersonate users, run the below PowerShell command:

$cred = Get-Credential

$session = New-PSSession -ConfigurationName Microsoft.Exchange -ConnectionUri https://ps.outlook.com/powershell/ -Credential $cred -Authentication Basic -AllowRedirection

Import-PSSession $session


New-ManagementRoleAssi​gnment -Role ApplicationImpersonation -User <admin_user_name>

Remove-PSSession $session

More information about this PowerShell command can be found here.


  • MigrationWiz uses delegation by default to log in to individual user mailboxes using administrative credentials specified on the connector. 

It is highly recommended to use impersonation when migrating from or to Office 365.


Using impersonation, it is possible to stop sharing the throttling quota and connection limits associated with a single administrative account. ​Instead, the throttling quota of each user is used to log in to each user mailbox.

Using impersonation means:

  • Eliminating most "Connection did not succeed" errors
  • Allowing migration of more mailboxes concurrently
  • Reducing the impact of throttling and connection limits
  • Using an admin account without assigning a license to it

Full Access

To manually grant administrative access for migration, execute the following remote PowerShell commands: 

$cred = Get-Credential

$session = New-PSSession -ConfigurationName Microsoft.Exchange -ConnectionUri https://ps.outlook.com/powershell/ -Credential $cred -Authentication Basic -AllowRedirection

Import-PSSession $session

Get-Mailbox -ResultSize Unlimited | Add-MailboxPermission -AccessRights FullAccess -Automapping $false -User MigrationWiz

Remove-PSSession $session


  • 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.
  • In the script above, the username "MigrationWiz" should be replaced with the name of the administrative account that was set up, by following the instructions in this Knowledge Base article.
  • This username is the Administrative Username that needs to be entered under the project's Source or Destination settings, within MigrationWiz, when checking the box labeled Use Administrative Login.

 Create and License User Accounts

 Set up accounts on Office 365 and assign licenses. These can be created in several ways:

Additional Configuration

The following configuration is recommended for all migrations to an Office 365 tenant:


Licenses are required to run a migration project in MigrationWiz. To obtain license pricing information, or to purchase licenses, click the Purchase button in the top of your MSPComplete or MigrationWiz dashboard.

Payment: We accept credit cards, and wire transfer in certain situations.  

  • When purchasing with a credit card, payment is immediately processed during checkout. If successful, licenses are granted to your account instantly.
  • Wire transfers are available for purchases of 100 or more licenses. If you are purchasing at least 100 licenses, you will be presented an option to purchase via wire transfer during checkout. A wire transfer checkout will generate an invoice with wiring information for your accounts payable department and bank. Once the funds are received by our system, the licenses are granted to your account immediately. 

For this project type it is recommended to use our User Migration Bundle licenses. 

  • These licenses enable you to perform multiple migrations of User mailboxes, documents, and in-place archives, and allows the use of DeploymentPro to perform post-migration Outlook email profile configuration.
  • Further information on User Migration Bundle Licenses:
    • User Migration Bundle Licenses have unlimited data available per license.
    • User Migration Bundle Licenses are applied to the customer's users, for whom you'll be performing migrations, and are valid for one year.
    • Read the Apply User Migration Bundle Licenses to the Customer's Users article for more information about how to apply the licenses to Users for migrations.

Create A Mailbox Project

Create a Mailbox Migration Project

  1. Click Go To My Projects
  2. Click Create Project
  3. Select a Mailbox migration type. 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.
  4. Click Next Step.
  5. Enter a Project name and select a Customer.
  6. Click Next Step.
  7. Select a Source Endpoint from the Endpoint drop-down menu. If an Endpoint has not been created, click New and provide the requested information in the Endpoint creation flyout window.
  8. Select a Destination Endpoint from the Endpoint drop-down menu. If an Endpoint has not been created, click New and provide the requested information in the Endpoint creation flyout window.

    1. When creating the project on your Source Settings or Destination Settings tab, click New.
    2. Fill in the fields below. Once endpoint has been saved in the project, it will automatically be assigned to the customer that was selected in the Project Information tab when creating the project.
    • Name: Type any name you want for the endpoint.
    • Find My Service Provider: Use this control only if the endpoint you’re creating is hosted by a service provider and not a local endpoint. If you don’t know your server type, click this button and then click your provider in the drop-down list.
    • Endpoint Type: Click the Endpoint Type drop-down, and then click the appropriate endpoint type in the list. Ensure you have selected the correct source and destination. When you select an endpoint type, the form will expand so that you can provide additional connection information and credentials for that endpoint type. These additional fields vary depending on the endpoint type.
    • If an endpoint does not exist for the service that you want to connect to with MigrationWiz, then use the Generic endpoint type to generically store the web address for that service, a username, and password. This endpoint can still be used for Runbook execution.
    • Provide credentials: Select Provide Credentials or Do Not Provide Credentials as needed.
    • If you select Provide credentials, the form expands to present more fields for username and password. The credentials will be used by MigrationWiz to access the service selected. In most cases, you must provide credentials for an administrator account on those services, as this will enable MigrationWiz to have full access to the cloud service.
    • If you select Do not provide credentials, then MigrationWiz will request credentials from end users before a migration can be started, or before a Runbook can be completed. This may slow your migration, as you are now dependent on the end users to provide these credentials.
    • Domains: For migrations using G Suite Endpoints, this is the list of domains that you will be migrating to, or migrating from. This is not relevant to any other migration environment.
    • Use SSL: For some endpoint types, there is an SSL check box at the bottom of the form. Select this check box if you want to secure your new endpoint with Secure Sockets Layer (SSL).
    • Note that IMAP and POP endpoints include an SSL option (check box): If your provider uses SSL, you should select this check box and enter the SSL port number in the field provided. For IMAP endpoints, the default port number for SSL is 993. For POP endpoints, the default port number for SSL is 995.
    • If your provider does not use SSL, do not select this check box, and enter the non-SSL port number in the field provided. For IMAP endpoints, the default port number for non-SSL is 143. For POP endpoints, the default port number for non-SSL is 110.
  9. Click Save and Go to Summary

Add Accounts (Items)

Add the accounts that will be migrated, also referred to as items, to a project using one of the following options:

  • Quick Add: This option allows you to add items o​ne at a time. You have to enter an email address, login name, and password for each user if you didn't enter administrative credentials when setting up the project. You only have to provide an email address if you entered administrative credentials when setting up the project.
  • Autodiscover Items: MigrationWiz detects the mailboxes directly at the Source using Autodiscover. For more information, refer to How do I Autodiscover Items for my Migration.
    • For mailbox migrations, this feature is only supported when the Source is Exchange 2007 or later, when the Source is Office 365, or when the Source is G Suite.
    • This feature is not supported for in-place archive migration projects, even if the Source is Exchange 2007 or later.
  • Bulk Add: This option allows you to add multiple items at once by copying and pasting from a spreadsheet or by importing a CSV file. The domain names at the Source and at the Destination might be different. Make sure to provide the right information in the project. If they are different, it's best to modify these in your CSV file, and then use the Bulk Add feature to import the users into the dashboard.
    • Select the Project for which you want to perform the bulk import.
    • Click on Add.
    • Click on Bulk Add.
    • Follow the instructions on the page.

Set Advanced and Support Options

Advanced Options allow you to choose your notifications, filtering, maintenance, licensing, performance, and some configuration options.

Support Options are advanced configurations that make use of Powershell or code blocks to provide extra options or resources for your migration.

For a full explanation and FAQ about Advanced & Support Options, see What Project Advanced Options are Available and MigrationWiz Support Options.

The following options are the most valuable for this migration scenario:

Global Options

The following options are most valuable for all G Suite migration scenarios:
  • Under Support/Support options, add: StoreOverflowGooglePropertiesInNotes=1 KB005056
  • Under Support/Support options, add: StoreOverflowGooglePropertiesInNotesPrefix="enter your text here" KB005056 (Replace "enter your text here" with your message. Please see KB005056)
  • Under Support/Support options, add: SuppressReminderDays=X KB004203 (Replace "X" with a value from 1 to 365. Please see KB004203)

Run Migration

Remove the All Mail filter from Project Advanced Options, and run one final full migration pass.

    • Under Project Advanced Options > Filtering section, delete: (^All Mail$|^All Mail/) KB005626
    • Select the users > Click the Start button from the top, select Full Migration > Click Start Migration.
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