Office 365 to G Suite Migration Guide

Overview:

  1. Performing mail migration with Cloudiway
    1. Cutover migration
      1. Cutover migration benefits
      2. Cutover migration considerations
    2. Staged migration
      1. Staged migration benefits
      2. Staged migration considerations
    3. Supplementary tools
        1. Calendar free/busy
  2. Security
  3. Performance
  4. Mail migration scope
    1. What can be migrated?
    2. Migration limitations
    3. Considerations
    4. Audience
  5. Pre-migration configuration
    1. Before you start
    2. G Suite — Set permissions for Cloudiway service account
    3. Office 365 — Set up an account with impersonation privileges
    4. Recreate your resources (using provisioning)
  6. Use the Cloudiway platform to migrate your mail
    1. Create your G Suite source connector
    2. Create your Office 365 target connector
    3. Configure the global settings for migration
    4. Import or create your users
      1. Option 1: CSV import
      2. Option 2: Import Users tool
      3. Option 3: Single user creation details
    5. Recreate your resources (using provisioning)
    6. Activate and monitor your migration
    7. Migrate permissions globally
  7. Troubleshooting

1. Office 365 to G Suite migration with Cloudiway

Cloudiway’s mail migration solution helps businesses perform elaborate technical migrations through a simple cloud interface. As a result, mail migrations require no additional software installation or overhead, and migrations can be performed securely and quickly.

The Cloudiway platform is flexible enough to support all types of migration paths. Your migration strategy will depend on your business setup, type and size. Whichever migration path you choose, Cloudiway provides all the essential features including automatic account provisioning, license assignment, archive migration, mail routing and calendar coexistence (free/busy scheduling).

Two of the most common migration strategies are cutover and staged migrations. Cutover strategies involve migrating all mailboxes over a weekend, ready for your users on Monday morning. Staged strategies provide more flexible migration options, as discussed below.

1.1. Cutover migration strategy

You migrate everybody over a weekend. This strategy is the simplest to implement. You can migrate your mailboxes in a single pass migration or envisage a pre-staging strategy where you run multiple migration passes.

Cutover migration is, therefore, a strategy where the entire company is switched at the same time.

1.1.1. Cutover migration benefits

  • Fastest, simplest form of migration.
  • Your users can start using the new mail system immediately.
  • New emails are received in the target messaging system.
  • Old emails are migrated in a single pass.

1.1.2. Cutover migration considerations

You can combine your cutover migration with pre-staging if required. In this case, during the days or weeks leading up to your cutover, you would migrate all emails up to a week or so ago along with calendars and contacts, then on the day of your cutover, you would run a quick delta pass to migrate the remaining items.

1.2. Staged migration strategy

A staged migration allows you to migrate batches of mailboxes over the course of a few weeks or months. This strategy is useful for migrations with large volumes of data (full mailboxes or many mailboxes) and you estimate that you won’t be able to do your migration over a single weekend.

Cloudiway offers you additional flexibility in your approach to a staged migration. For example, you could migrate the last six months of emails over a weekend and leave older emails and email archives to be migrated after cutover, explaining to users that their older emails will appear soon.

Prestaging is also an option on the Cloudiway platform. For example, you could perform a multi-pass migration where you migrate most mailbox items before performing the final cutover. During the days or weeks leading up to your cutover, you would migrate all emails up to a week or so ago along with calendars and contacts, then on the day of your cutover, you would run a quick delta pass to migrate the remaining items.

Cloudiway provides several options to help you find the best strategy for a staged mail migration. We provide coexistence services, plus mail routing, and batch migration of users, which you can define in any way you like. Basically, you can choose who, when and what gets migrated during each pass.

1.2.1. Staged migration benefits

  • Many flexible migration strategies when using the Cloudiway platform.
  • Allows more time before final cutover, avoiding tight deadlines.
  • Complex migrations can be completed without disrupting end users.
  • Can be performed in batches according to your needs.

1.2.2. Staged migration considerations

Staged migrations tend to be more complicated than single cutover migrations. Therefore, it’s important that you have planned your approach thoroughly prior to starting any migration.

1.3. Supplementary tools

Cloudiway has developed a number of tools to enable seamless migration for the most intricate migrations. Our supplementary tools include:

  • automatic account provisioning (users, distribution lists, shared contacts);
  • mail routing; and
  • calendar free/busy display.

These tools are available as additional modules, and therefore incur an extra cost. Please contact us for more information on presales@cloudiway.com.

1.3.1. Calendar free/busy

Cloudiway provides a coexistence tool for calendar free/busy time display. For example, a G Suite user on one can check the free/busy time of an Office 365 user. Coexistence manages cross-platform communication with no impact on the end user. It provides a seamless connection between two different remote systems during the migration.

To discuss any of these supplementary tools further, please get in touch with your existing Cloudiway contact, or via sales@cloudiway.com.

2. Security

We take your privacy and security seriously at Cloudiway, and we have invested significant effort into making our platform and your data secure. Cloudiway provides a cloud-based application hosted on Windows Azure. It means that the software and data are centrally hosted and accessed by clients using a web browser and internet connection. In addition, Cloudiway’s SaaS benefits from Windows Azure’s certifications, ensuring the security of the infrastructure, network and physical security layers of the Cloudiway cloud.

For total assurance, Cloudiway provides auditing tools, secure, authenticated data connections and a logging system. More specifically:

  • Cloudiway doesn’t store your mail, files or site data
  • the migration takes place in memory only: the migration engine connects to the source, pulls data and pushes it in real time;
  • connections to the source and the target are done using HTTPS so no data is transferred unencrypted over the internet; and,
  • nothing is stored internally: no data persists in the platform.*

*For the delta pass mechanism, the messageID of each email is used. This ensures that no data is duplicated, and for efficiency, only the changes are propagated. We automatically delete inactive records after 90 days, or upon request.

In addition, because the Cloudiway platform needs credentials to connect to the source and the target, you define connectors to connect to them and enter credentials that will be used for the connection. These credentials are stored encrypted using AES 256.

For complete peace of mind, we recommend that you create a temporary migration account during your migration which you can delete at the completion of your project.

3. Performance

There are several considerations regarding email migration performance. The Cloudiway migration platform uses all available resources to provide the fastest migration possible and can support both small and large migrations. The on-demand migration engine allocates the capacity that you need to migrate the volume of data of your choice in the time slot you have allocated.

However, there are limitations. Many mail systems can heavily throttle users. When you perform too many calls, the remote server will begin throttling and decrease the number of calls that can be performed each minute, thus reducing the migration throughput. Cloudiway constantly attempts to work at the maximum capacity allowed to achieve excellent throughput.

Google Limitations

Google limits migration to 2.5 GB per user per day. Usually, some additional data migration is possible before throttling begins. When throttling does begin, the Cloudiway platform will attempt to migrate 10 GB of data per user, then sleep for 6 hours and automatically restart the migration where it left off.

Office 365 limitations

Office 365 uses throttling policies to limit the resources consumed by a single account. To maximize throughput and limit throttling, Cloudiway follows Microsoft best practice and uses impersonation.

An account that has impersonation privileges can impersonate 100 users concurrently to migrate 100 mailboxes in parallel. The platform uses EWS (Exchange Web services) protocol; Microsoft theoretically allows throughput of around 300 MB per user per hour. The Cloudiway platform typically sees throughput between 200 Mb and 300 MB per mailbox per hour. This gives an average throughput of around 500 GB per day with a constant migration of 100 concurrent mailboxes.

If you wish to further improve throughput, you can create distinct migration accounts and create additional connectors in the platform. For example, if you create two targets Office 365 connectors (each with its own distinct migration account), you can migrate 200 mailboxes concurrently and reach a throughput of around 1 TB per day.

4. Mail migration scope

4.1. What can be migrated?

When migrating from Office 365 to G Suite, all the following mail-related items can be migrated:

  • Emails
  • Shared mailboxes
  • Contacts
  • Calendars
  • Secondary calendars
  • Distribution lists
  • Folders
  • Delegations and permissions
  • Rooms and equipment
  • Tasks
  • Journal
  • Notes
  • Inbound Rules
  • Litigation hold folders
  • Online archives

4.2. Migration limitations

G Suite uses labels rather than folders to organize emails, and users can apply multiple labels to a single email. Office 365 mail doesn’t use labels, so storage for each email is limited to one folder. The Cloudiway platform takes the folder in Office 365 and creates one label with the same name, where the email will be stored.

Currently, inbound rules (including out of office rules) are not migrated from Office 365 to G Suite.

4.3. Considerations

Migration takes place between existing mailboxes. This means that mailboxes must exist in the target at the time of migration. Before starting a migration, please ensure that all mailboxes to be migrated have had their target mailbox created in the target domain (steps are included in this guide).

4.4. Audience

This guide is aimed at experienced system administrators who are capable of connecting to remote systems and using a variety of administration tools.

Although we provide support for our own products, we do not provide support for third-party products such as PowerShell or server administration of Google or Exchange.

If you are concerned you might have any difficulty completing these steps, please consider a solution with our consulting team, presales@cloudiway.com. We will ensure a fast, cost-effective and stress-free implementation.

5. Pre-migration configuration

5.1. Before you start

Before you start, you will need to ensure you have the details outlined in the following table.

Name Description Location
Cloudiway login Stores details and provides communication between the systems you already use. https://apps.cloudiway.com
Knowledge base access Our extensive knowledge base is always accessible, with videos, troubleshooting tools, samples and more. https://kb.cloudiway.com
G Suite API console Required to enable APIs and to download the G Suite private key. This can be accessed via your Google Admin account. https://console.developers.google.com
Google Admin console The Admin console is where administrators manage Google services for people in an organization. https://admin.google.com
Office 365
account with
impersonation
privileges
Used for impersonation to access mailboxes (read or write). This doesn’t have to be the tenant’s admin account. However, it must be an administrator account if you wish to migrate the permissions. The account must be able to bypass SSO and authenticate using username/password credentials with the format: user@tenant.onmicrosoft.com (with a password set to never expire). Exchange Admin Center.

We recommend you create a nonfederated domain account (on your *.onmicrosoft.com domain), especially for mail migration. After all, migrations are complete, simply delete this account. We provide steps below to help you set up an account with impersonation privileges if you don’t already have one.

 

5.2. G Suite — Set permissions for the service account

  1. Go to https://admin.google.com and log in with your Admin console credentials
  2. Click on Security, then Advanced settings (you might need to click on Show more to see this)
  3. Click on Manage API client access
  4. In the Client Name: paste 114818336788408865729
  5. Click on the One Or More API Scopes field and add the following scope:
    https://www.googleapis.com/auth/admin.directory.resource.calendar,
    https://www.googleapis.com/auth/calendar,
    https://www.googleapis.com/auth/gmail.labels,
    https://www.googleapis.com/auth/tasks,
    https://www.googleapis.com/auth/gmail.insert,
    https://www.googleapis.com/auth/gmail.readonly,
    https://www.googleapis.com/auth/contacts,
    https://www.googleapis.com/auth/gmail.imap_admin

    NOTE:

    1. Each scope must be separated by a comma.
    2. Some scopes require slashes (/) at the end and others don’t: please use the above strings.
    3. If you add another scope later, existing scopes will be removed: you need to add the whole list at the same time.

  6. Click on the Authorize button
  7. You can check that the scopes were successfully registered by looking for the names next to the client ID you paste
  8. Now, navigate to Security > API Reference > API Access and ensure that ‘Enable API Access’ is checked. 

5.3. Office 365 — Set up an account with impersonation privileges

An Office 365 account with impersonation privileges can access up to 100 mailboxes concurrently. Therefore, by default, Cloudiway allows you to migrate 100 concurrent users in an Office connector. If you wish to speed up your migration, you should set up additional Office 365 target connectors on the Cloudiway platform and associate different accounts with admin access to each one. These can be connected to a single G Suite source connector.

Below are the steps to show you how to set up an impersonation using the Office 365 Exchange Admin Center. If you don’t already have impersonation set up, please follow the steps below.

  1. Log in to your administrator account to the Office 365 portal
  2. Go to the Exchange admin center, then click on permissions and the admin roles
  3. Click on the plus sign (+) to create a new role
  4. Give your group a name and assign it the role of ApplicationImpersonation, then add a user to the group: 
  5. Click on the Save button to save your group

5.4. Recreate your resources (using provisioning)

Resources from your source must be available on your target before migration can begin. Cloudiway provides a tool to automatically recreate rooms and equipment for migrations from Office 365 to G Suite, which will be explained later in this guide. Cloudiway can also recreate shared mailboxes in the target, but this tool is not yet available on the platform. If you’d like a preview, please get in touch via sales@cloudiway.com.

6. Use the Cloudiway platform to migrate mailboxes from Office 365 to G Suite

6.1. Create your Office 365 source connector

For Cloudiway to migrate your email, it needs to be able to communicate with both your source and target domains. To do this, Cloudiway uses connectors, which are configured on apps.cloudiway.com. You will need to set up a connector for each source tenant you wish to migrate and each target tenant that mail should be migrated to. Follow the steps below to configure an Office 365 source connector.

Each account with impersonation privileges can access up to 100 mailboxes concurrently. Therefore, by default, each Cloudiway connector can migrate 100 concurrent users. If you wish to speed up your migration, you should set up additional Office 365 connectors on the Cloudiway platform and associate different accounts with admin access to each one.

  1. From your browser, go to https://apps.cloudiway.com and login
  2. Click on Mail Migration on the left, then Targets
  3. Click on the + New option at the bottom of the screen
  4. Click on Office 365 and type a meaningful name in Connector name
  5. Click on the Create button
  6. Type your target domain name in Domain
  7. Type your Office 365 account credentials (with administrator and impersonation rights)
  8.  
  9. The remaining field is for archiving older emails from inboxes (switched off by default):
  10. For now, click on the Save button without activating this option (it’s covered in the next section).

With the source connector now configured on the Cloudiway platform, it’s time to create and configure the target connector. Follow the steps below to configure a Gmail target connector.

  1. From your browser, go to https://apps.cloudiway.com and login
  2. Click on Mail Migration on the left, then Sources
  3. Click on the + New option at the bottom of the screen
  4. Click on Google Gmail and type a meaningful name in Connector name
  5. Click on the Create button
  6. Click on the Save button at the bottom of the screen Your source connector has now been created. Next up is the target connector

6.4. Configure the global settings for migration

Now that you have set up at least one source and target connector, you’re ready to configure your global settings. Using the Cloudiway platform, this is simply a matter of selecting what you want to migrate.

By default, the global migration settings are configured to migrate everything but the Trash folder. You can toggle these from the Global Settings option on the Cloudiway platform. You can also specify which emails to migrate according to their date and timestamp (in UTC).

Most of the options are self-explanatory. The Convert Email Address option needs further explanation. When activated, this option rewrites email addresses found in the header and replaces source email addresses with their corresponding target email addresses.

For example, if Bob sends an email to his colleague to Chloe from his source address bob@source.com to chloe@source.com and a week later, after migration, chloe@target.com replies to Bob, the Cloudiway platform has already updated SMTP header in Bob’s original email in her inbox, so her reply will be sent to bob@target.com.

For migrations where the only email address change is the domain name (such as Bob’s email address above), the Cloudiway platform uses the domain name defined in the target connector to convert source email addresses.

For migrations where both the domain name and the username change (for example, bob@source.com becomes newbob@target.com), the Cloudiway platform already uses a mapping table to link each user. This mapping table is also used by the Convert Email Addresses option in this situation. Therefore, it’s important that all users exist in the mapping table before migration begins (this guide contains instructions).

Note that users in the mapping table do not require a license until you’re ready to migrate them. Therefore, you can assign the free ‘No license’ option to all your users prior to migration. Having a complete mapping table is also required if you plan to use Cloudiway’s free/busy calendar tool in conjunction with mail migration.

The Convert Email Address option is switched on by default (and is best left on). Make sure your user list is up to date to benefit from this functionality.

Convert X500 Email Address is not used for the G Suite Migration

From the same Mail Migration area of https://apps.cloudiway.com, click on Global settings by default

  • The global migration settings are configured to migrate everything but the Trash folder. You can toggle these and change the date and time settings in Edit mode. Please refer to the text above these steps for more information on the Convert Email Addresses option.
  • Click on the Edit button at the bottom of the screen The grey buttons will turn blue, indicating you can now edit these to your preferred global migration plan.
  • Update any settings you wish to alter, remembering that time and dates are set to the UTC time zone
  • Click on the Save button at the bottom of the screen to update your global settings

6.5. Import or create your users

There are a number of ways to add users that you wish to migrate. These include:

  1. CSV file upload;
  2. Cloudiway’s Import Users tool (using IAM); and,
  3. Create a single user.

Regardless, each user will need to be assigned a license type — Trial (limited to 100 MB), Education, Standard, Archive, or No License (used for adding users to your mapping table regardless of migration plans).

6.5.1. Option 1: CSV import

If you have a CSV file of all your users, you can upload the file to Cloudiway. The file must have the following fields in the header row:

FirstName;LastName;SourceEmail;TargetEmail;BatchName

Note that many browsers limit CSV file uploads to 5000 lines, so files larger than that should be split up and uploaded separately. Data already uploaded will not be overwritten, so you can upload as many files as required.

The BatchName field can be left blank. If required, you can use this field to name different batches so they can be run in a certain order. A sample CSV file is available for download during the steps outlined below.

  1. Ensure you’re still in the Mail Migration area of apps.cloudiway.com and go to User List
  2. Click on Manage and Upload CSV in the bottom left corner and select Upload CSV
  3.  
  4. If required, click on Download sample CSV and add your users to the CSV file using the sample headers (FirstName;LastName;SourceEmail;TargetEmail;BatchName)
  5. When you have a complete CSV file with the correct headers, click on the Upload button
  6. Locate your CSV file within your own file system, and double-click on it to select it
  7. Select the appropriate connectors in the Source and Target fields
  8. Select the license type from the License drop-down list
  9. Click on the Upload button.
    If the CSV file format is not correct, you will see an error message on your screen:
  10. If you see any error messages, check your CSV file to ensure it has five columns, each with a separator (including the last) and try uploading again
  11. Once the CSV file format is correct, you will see a confirmation message at the top of your screen:
  12. Check your email. When you have received confirmation that the upload has been completed, you can refresh the Cloudiway platform to display your imported users

6.5.2. Option 2: Import Users tool

Cloudiway’s Import Users tool helps you to retrieve users from your source tenant. The functionality works via Identity Access Management. The tool requires you to specify any transformation rules you wish to apply. It will then add new users in the Mail Migration User List view within the Cloudiway platform.

This is an advanced tool that is best used in partnership with Cloudiway consultants. If you are interested in using this option, please get in touch with your Cloudiway contact.

6.5.3. Option 3: Single user creation details

Many of our first-time customers create a single user for testing purposes. This provides a means of watching the migration process without affecting all users. Single users can also be created for migrations affecting just a few users.

  1. Go to the User List of the Mail Migration menu
  2. Click on Manage in the bottom left corner and select Create Single to display the following screen:
  3. Fill in all details for a new user
  4. Click on the Create button
    The new user will be added to the Mail Migration / User List screen:
  5. Repeat steps 1 to 4 for any more users you’d like to create

6.6. Recreate your resources (using provisioning)

The Cloudiway platform provides a free resource creation tool to customers performing mail migrations from G Suite to Office 365. Recreate rooms and equipment using the steps below.

  1. From the same Mail Migration area of https://apps.cloudiway.com, click on Global Actions
  2. Click on the Create Rooms & Equipment option to display the following dialogue box:
  3. Select the source that contains the rooms and equipment to be provisioned
  4. Click on the Create button to trigger the process
    The dialogue box will disappear and you will receive a confirmation on your screen that the process has begun.

  5. You can watch further progress by refreshing the Global Actions screen, where a progress bar will be displayed during processing, and ‘DONE’ will be displayed when the process is complete.
  6. Click on the User List sub-menu of the Mail Migration area and verify that all resources have been created.

6.7. Activate and monitor your migration

Now that you have performed all the pre-migration steps within your tenants and within Cloudiway, you’re ready to migrate. We recommend you run a test migration on a single user first to check that your configuration produces the outcome you expect.

To start your migration, select the users or batch you wish to migrate and click on the Start button. Your batch will be scheduled and will begin as soon as resources are available. By default, a hundred migrations can be run concurrently per connector.

Don’t forget that Cloudiway migration platform supports delta passes and that migrations are therefore incremental; every time you restart the migration of a mailbox, only items that haven’t already been copied to the target will be migrated. The platform, therefore, does not duplicate items in the target.

6.8. Migrate permissions globally

You can globally migrate permissions for mailboxes through the Cloudiway platform.

NOTE: Once you start the process of setting permissions, it cannot be stopped.

  1. From the same Mail Migration area of https://apps.cloudiway.com, click on Global Actions:
  2. Click on the Migrate Permissions option on the screen to display the following dialog box:
  3. Click on the Set button to trigger the Cloudiway platform into setting permissions on all mailboxes

8. Troubleshooting

Cloudiway provides an extensive knowledge base with many resources, including common error messages, video guides and downloads.

Please visit the entire knowledge base here (where you can search for keywords or read through topics): https://kb.cloudiway.com/

The knowledge base also contains information on how you can ask for further support, should you require it.lick on Security, then Advanced settings (you might need to click on Show more to see this)

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