Migrating Calendars from Google Mail to MS Exchange Server

Migrating Calendars from Google Mail to MS Exchange Server

In order to migrate Google Mail Calendars to an MS Exchange Server using Mail Data Migrator tool, there are some prerequisites that must be followed. They are as under :

  • Gmail App Registration (Calendar API Registration)
  • Configurations required in Mail Data Migrator Application for Google Calendars

Gmail App Registration
This process consists of the following steps :
  1. Prior to following the points make it sure that your Google Mail account is configured to allow less secure apps. You may enable less secure app option by navigating to the URL : https://myaccount.google.com/lesssecureapps
  2. Open this URL : https://console.developers.google.com using Gmail credentials.
  3. Now create New Project by clicking on Create project as shown in screenshot given below :
4. Once the project is created, click on Enable APIs And Services as shown below.

 5. Search for “Google Calendar API” and click on it. 

Click on “Enable” button to enable "Google Calendar API".

  1.  Now create credentials for API.

5. Click on “Create Credentials”

Now OAuth Client for Google Calendars will be setup after clicking Create button in above screenshot and the application will be registered successfully.

Important Note : here is in the “Redirect Uri” after the Domain e.g. http://localhost:1122 you have to add “/Home/CalendarAccessToken

In this step, edit this newly registered app and copy the values of "Client id" , "Client secret key" and “Redirect URI” as shown in below screenshot by editing the application.

 Configurations required in Mail Data Migrator Application for Google Tasks

The steps given below are required for configuring Google Calendars to migrate to another target server.

1. Now Copy Google Client ID, Client Secret and Redirect URI from previous step and specify these new values in Mail Data Migrator tool. See below screenshot for further clarity :

Once both Source Google Mail and Target Mail Server connections are verified, add mailbox by clicking on Add >> Add Mailbox link. Provide Google Mail ID of your mailbox, and then click on Save button (Note: Do not provide any password for this mailbox rather keep it blank)

4. Once you click on save button below screen will appear and you will be sent an email on your google mail account to verify your account.

  1.  Email notification is sent on source Mailbox as shown below.

  1. Now user will sign into Mail Data Migrator panel by following email notification.

  1. If source mailbox is Gmail then Mail Data Migrator will redirect the user to service verification screen, asking user for permissions.

  1. Registered application is not verified by google, it should be sent to google for verification. Therefore, click on Go to (Unsafe) option.
  7. Grant “Mail Data Migrator” webapplication, the permissions on Google Calendars as you are redirected to google consent page 


  8. If all services are verified, user will be redirected to Add Target Mailbox screen, otherwise it will be redirected to Service Verification Screen for verification of remaining services.