The complete journey from Google to Exchange Online with Free/Busy rich coexistence

When questioned by partners, on what is the best approach to plan and execute a move of a customer’s email system, from G-Suite to Exchange Online in Office 365, the first questions that I ask are:

How many users do you have to migrate?

Are you going to do a migration in batches (Staged) or cut over all users at the same time?

Usually when there’s a large number of users, the migration in batches is the preferred option. At that point you should consider two things:

  • How can I automate the mail flow changes
  • How can I have free/busy coexistence between G-Suite and Office 365

The answer to both questions above is simple: You can automate the mail flow and have free/busy coexistence if you use BitTitan MigrationWiz to move the mailboxes, and the BitTitan automation processes to help you with the changes you need to do per migration batch.

In the past I wrote an article on how to configure mail flow coexistence between Google Apps and Office 365, that can help you understand the configurations you need to do.

BitTitan also has a very good article on how you can automate the mail flow changes, on a mail migration from Google to Office 365, as well as the entire migration guide.

But I want to focus this article more on the free/busy rich coexistence, between Google and Office 365, the value that it brings to your migration and your customer, a technical overview on how it works, and of course how you can configure it.

What is the value on having free/busy coexistence between G-Suite mail and Office 365 Exchange online

User experience. It’s all about the user experience!!! If you are moving a 20k users company from Google to Office 365, you often get questioned about what the migration journey will mean for the end users, in terms of end user experience. When you provide your customer and their end users the ability to have not only mail flow coexistence (that one is mandatory of course) but also calendar free/busy lookup capabilities, you’re giving them the best experience they can have.

I have also seen more and more companies using the BitTitan Google coexistence tool for permanent free/busy coexistence between G-Suite and Exchange Online, so don’t think about it just like an add-on to a migration project, it can be much more than that.

How can I achieve that with BitTitan

Currently BitTitan will allow you to use the Google coexistence tool for free during 3 months, if you use BitTitan MigrationWiz to move all of the mailboxes. If you want coexistence for more than 3 months, or if you’re not using MigrationWiz, you will be quoted a price per user per month.

Note: The statement above was true when I wrote this article. There no guarantee that will be true when you read it so please contNact BitTitan for more information.

Why do I need a free/busy coexistence tool between Google and Office 365

The answer to this is short and simple: the Google Calendar Interop, which is the tool that you need to configure on your Google tenant to query free/busy from Exchange mail systems, cannot query free/busy information, from an Exchange Online mailbox, via the Exchange Web Services API and the Availability Service. Instead it will try and query free/busy information from an Exchange Public folder. The problem is that the newer versions of Exchange don’t support that method anymore.

So in essence, because the Google Calendar Interop hasn’t evolved to match the changes that the Microsoft Exchange product group implemented in the way the free/busy is queried, specifically on the transition from Exchange 2010 to Exchange 2013, you need a translation tool between Google and Office 365. That translation tool is the BitTitan Google Coexistence tool.

How do I configure the BitTitan Google coexistence tool

The answer is, you don’t. You configure the Google Calendar Interop and Exchange Online by creating an Organization Relationship, both to point to the BitTitan Coexistence service, and you also create a MigrationWiz project in the BitTitan portal, so that you can obtain your authentication token from the BitTitan Support (support@bittitan.com). See here the coexistence setup guide.

This is how the Google calendar interop should look like:

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And to configure the calendar interop:

  1. login to https://admin.google.com
  2. Go to Apps > G Suite > Calendar > Calendar Interop Management
  3. Enter all the information as per the coexistence setup guide

This is how the Exchange Online Organization Relationship should look like:

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And to configure the Organization Relationship:

  1. Download the Coexistence script from the BitTitan setup guide
  2. Add the details to the script as per instructions on the setup guide
  3. Open an Exchange Online PowerShell session
  4. run the script
  5. Verify if the Organization Relationship was properly created by running: Get-OrganizationRelationship |fl

Do I need contacts in each organization for the free/busy to work

No, you don’t need a contact in Google for each user from Exchange Online that you want to query the free/busy, nor you need them in Office 365 for each Google user. You should have contacts in both sides, but to make sure you have a unified Global Address list.

To be clear on this:

  • Peter@domain.com is a Google mailbox
  • John@domain.com is an Office 365 mailbox
  • You don’t need to create peter@domain.com as an Office 365 mail contact
  • You don’t need to create john@domain.com as a Google mail contact

But again.. you should.. having a unified GAL is usually mandatory and for sure highly recommended.

How do users query the free/busy information

As they do for any other internal user. They open their calendar app and enter the email address of the user on the other system or search for his contact created on the GAL if it exists.

To wrap this up, and please stay tuned for more blog post on this subject coming soon, the rich coexistence (mail flow and free busy) experience, when you’re migrating your customer from Google to Office 365, is very important and also very easy to achieve.

If you have any questions please feel free to reach out. I can help you understand it better as well as configure it.

As always I hope this post was helpful.

PS- The BitTitan coexistence tool also works between Google and Exchange 2010 Sp2+ on premises.

 

 

 

 

How to configure mail flow coexistence between GApps and O365 using internal relay domains and mail users

Are you planning to move your e-mail system from Google Apps to Office 365? Do you have a large number of users, and therefore migrate the users in stages, and therefore set up mail flow coexistence between the two systems? Keep reading.

On this blog post I am going to guide you through the process of setting up mail flow coexistence, between Google Apps and Office 365.

There are several ways to achieve the mail flow coexistence, from an Office 365 perspective, such as:

  • The Internal relay domain with mail users method
  • The Criteria Based Routing method

This blog article will guide you through the mail flow coexistence configuration, using the internal relay domain method. This method as some pros and cons when compared to others, such as:

Pros:

  • Easy to configure
  • If the processes are well defined it’s also easy to manage as the migration goes along

Cons:

  • Requires more processes during the migration stage
  • Requires more changes post migration
  • When not using Dirsync or AADsync the users on Office 365 need to be created via the Exchange Admin Centre or the Exchange Online PowerShell, which makes the user creation process more complicated.
  • When you enable a mailbox on Office 365, for a user being migrated, all new e-mails coming from other Office 365 users (and external users if you already changed the MX record to Office 365), will not reach the Google Apps mailbox and stay only on the Office 365 mailbox. This makes that the process of migrating the user data has to be managed in batches of users, and done ideally over the weekend.

In my opinion, if you’re using Dirsync this method is an option you should consider.

Now let’s get what matters: the steps for configuring mail flow coexistence between Google Apps and Office 365.

Step 1 – Validate your domain on Office 365:

Of course if you are moving to Office 365, the first thing you need to make sure is that your domain is validated there, and enabled for Exchange Online.

On my scenario, the domain that I am using is myexchlab.com

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I am not going to give you a step by step guide on the simple tasks, such as adding and validating the domain on Office 365, to keep this blog post focused on the essential, which is to set up the mail flow coexistence.

As you can see above you need to make sure that your domain is added and validated, and that the domain purpose is set to ExchangeOnline.

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As you can also see above, on my Google Admin Portal, my domain is also validated and working there, as that is my current production environment.

Step 2 – Create and enable your Office 365 users as mail users

Depending on the way you create the users, they can already be mail users on Office 365, i.e. if you are using Dirsync or AADSync to push your users to Office 365, you should have them as mail users on premises, which will also make them mail users on Office 365.

To sum up, there are two ways to create all your users as mail users on Office 365:

  • If you’re using Dirsync enable them as mail users on premises and push them to Office 365
  • If you’re not using Dirsync you need to create all your users via the Exchange Online PowerShell, or the Exchange Admin Centre, directly as mail users. The reason is simple: In Office 365, it’s not supported to enable a user without Exchange attributes (just a regular MSOL user) as a mail user. The only way to give him Exchange attributes is to enable an Exchange Online license and create him a mailbox.

In my case I am not using Dirsync, so I am going to show you how to create all my users as mail users. To do so you can use a script (let me know if you need one), or do it manually via the Exchange Online management Shell.

Connect to the Exchange Online Powershell, and run the following cmdlet:

New-MailUser -Name “GApps1” -Alias Gapps1 -ExternalEmailAddress Gapps1@myexchlab.com -FirstName GApps1 -LastName 1 -MicrosoftOnlineServicesID GApps1@myexchlab.com -Password (ConvertTo-SecureString -String ‘P@ssw0rd’ -AsPlainText -Force)

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Repeat the step for each user you want to create.

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Now I have GApps1 and GApps2 created on Office 365, both users also exist and have their productions mailboxes on Google Apps.

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The users are also Exchange mail users, which is fundamental to have both an up to date Global Address list on Office 365, and to make the mail flow coexistence work.

I know that this way of creating the users might seem a bit manual, but there are two things you need to consider:

  • Most of you will be using Dirsync, which makes the user creation process much simpler.
  • You can script the user creation via the new-mailuser cmdlet and make your live easier.

Step 3 – Configure the routing domain in Office 365

In order to have mail flow coexistence between Google Apps and Office 365, you need to set up a forwarding address in each Google Apps user you move to Office 365. In order for it to work, the forwarding address needs to be from a sub domain of your main email domain. In my case I will use onprem.myexchlab.com which is a subdomain of myexchlab.com.

To properly configure the subdomain you need to:

  • Validate it on Office 365 and configure it for Exchange Online
  • Create an MX record for that subdomain, that points to office 365
  • Make sure that the users have a secondary SMTP address for that subdomain, that you will use as forwarding address on google

To validate the routing domain, go to the domains section on your Office 365 portal and click to add a domain.

As the domain is a subdomain of your main e-mail domain, the validation should be instant.

Skip the steps to add users, and make sure that you choose Exchange as domain purpose, as sown below.

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The Office 365 wizard will give you an option to add the DNS records (depending on your domain name provider), or you can just copy and paste the DNS records and add them yourself. The only relevant record that needs to be created, is the MX record.

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Make sure you verify that the MX record is created.

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Step 4 – Configure Exchange Online for mail flow coexistence

On the Exchange Admin Centre of your Office 365 tenant, you need to do two things:

  • Configure your main domain as internal relay
  • Create a send connector to send e-mail to your Google Apps

To configure your domain as internal relay, log in to your Office 365 tenant, and on the bottom left click on “Admin > Exchange”.

On the Exchange Admin Centre go to “Mail Flow” and click on the “Accepted Domains” tab.

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Select your main e-mail domain, in my case myexchlab.com, and click edit.

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Select “Internal Relay” and click save.

Now let’s create the send connector. On the Exchange Admin Centre, select “Mail Flow” and click on the “Connectors” tab.

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Click on the “+” to add a new connector.

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When creating the new connector, select from Office 365 and to your organization’s email server.

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Select a name and keep the existing options selected.

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Select “Only when email messages are sent to these domains” and click on “+” to add your main email domain.

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Enter one (or several) of the available Google Apps MX record as a smarthost.

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You can check the Google Apps MX records by doing an nslookup to your domain.

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Untick the always use TLS option and click next twice.

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Finally enter a valid e-mail address from your Google Apps environment, and click validate. Make sure the test succeeds.

Migration steps

Now that you have Office 365 configured for mail flow coexistence, let me give you a quick overview on the migration steps:

Define a migration batch

The first thing you need to do is define a group of users to be migrated. Because there’s no sharing of resources cross platforms (i.e calendars), I highly recommend you approach your migration batches on a per department basis. You might want to export all e-mail addresses of the users being migrated, into a CSV file, in order to use that file to script all the forthcoming tasks.

Activate the user licenses in Office 365

Once you have your group of users defined, you need to activate an Exchange Online license for them on Office 365. Like stated previously you can script that, but for the purposes of this blog post I will just activate the license manually, as the main goal here is to explain how to set up the mail flow coexistence.

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Go to your Office 365 admin portal, click on “Users > Active Users”, select the user you want to license and add an Exchange Online license.

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Via the Exchange Admin Centre you will be able to see that, the user is no longer a mail user, and it’s now a mailbox.

Note: As stated before, all e-mail coming from other Office 365 users, or external e-mail if you changed the MX record of your main domain to point to Office 365, will now stay on the GApps1 Office 365 mailbox and not on his Google Apps mailbox.

Migrate your user’s data

Now it’s time to push all the data from Google Apps to the newly created Office 365 mailbox. And how can you do that? Well the answer is simple: Use the best tool in the market. MigrationWiz from BitTitan.

https://www.bittitan.com/products/migrationwiz/about

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MigrationWiz will move all your emails, calendars and contacts, from Google Apps to Office 365. In addition you can also move your Google Drive and your Google Vault data, with other types of migrations supported by the same tool.

Set up the forwarding address on Google Apps

Now at the same time you start to move the data, you need to set up a forwarding address on the Google Apps accounts you’re migrating. I’ll be blogging soon an explanation on how MigrationWiz automatically sets that up for you, but for now I will again do it manually on my GApps1 user.

Log in to https://admin.google.com

Go to Users and click on the user you want to set up the forwarding. Click on “Account”.

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On the Email routing section add the forwarding address. Untick the “Change SMTP envelope”, the “Google Apps email” (leave a copy on the source) and the “Inherit routes from <your domain>”.

Important note: do not leave a copy on the source mailbox, or else when moving the data to Office 365 via MigrationWiz, you might get duplicates.

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Another thing that you need to make sure is that all the users being migrated have a @onprem.myexchlab.com secondary SMTP address.

Connect the users to Office 365

Once all the data is migrated all you have to do is set up your users to connect to Office 365 and start working there.

BitTitan also has a tool to help you automate that process: DeploymentPro

https://www.bittitan.com/products/deploymentpro/about

DeploymentPro will configure Outlook for all your users, and bring all attached PST files and signatures from the old profile (if applicable).

Test mail flow

Now that we’ve covered all the migration steps, it’s time to test mail flow between:

  • GApps1 that was migrated to Office 365
  • GApps2 still in Google Apps

Test message from the Internet to GApps1 (Office 365)

With the MX record still pointing to Google Apps, we will send a test message from the Internet to GApps1, that was already moved to Office 365.

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As you can see the message got delivered to Office 365.

Test message from GApps2 (Google Apps) to GApps1 (Office 365)

Now let’s send a message from a Google Apps user to an Office 365 user.

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And again message delivered to GApps1 Office 365 mailbox.

Test message from GApps1 (Office 365) to GApps2 (Goggle Apps)

Now the most relevant test, the one this blog post is all about: mail flow between Office 365 and Google Apps.

Let’s reply to the GApps2 email.

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And there you go. Working!

Internet mail flow considerations

On this coexistence scenario, there is no centralized outbound mail flow, which in essence means that Office 365 users will email directly to the Internet, and the same of course will happen to Goggle Apps users. Having said that, you need to make sure that your SPF record is up to date, and reflects that scenario. For help setting up your SPF record, go to the Microsoft SPF record wizard page.

Summary

Most of the configurations described above only need to be done once, but on the migration steps section you will want to automate everything. I’ve seen a lot of companies concerned with things like setting up the forwarding address on Google Apps, or scripting the way you enable licenses for users. One of my next blog post will be how MigrationWiz automates the forwarding address configuration, and you can ping me if you need more information about that, or if you need scripts for things like enabling the licenses on Office 365.

As stated on the beginning of this post, there are other methods to configure mail flow coexistence between Google Apps and Office 365, and I will soon be blogging about them so stay tuned.