Tips to Migrate Mailbox Over 100 GB to Office 365?

  

Rollins Duke   
Published: May 10th, 2024 • 7 Min Read

Microsoft 365 (Formerly Office 365) comes with a mailbox quota size limit so users face problems when they want to migrate mailbox over 100 GB to Office 365. But after reading this complete article anyone will be able to migrate over 100 GB users to Office 365.

Microsoft 365 Business Basic, Business Standard, and Enterprise E1 editions come with 50 GB Quota limit. While Office 365 Enterprise E3 and E5 editions provide 100 GB storage quota. Hence, sometimes the process to migrate over 100 GB users to Office 365 becomes very difficult due to lack of quota space.

Technical users and administrators know that On-Premises Exchange Server 2019 and 2016 editions don’t have a maximum mailbox size limit. However multiple factors affect server speed so most of the time users don’t prefer to increase mailbox size over 100 GB.

Recently one of our respected clients connected to BitRecover support team to learn the professional way to migrate mailbox over 100 GB to Office 365. Let’s read below.

User Query

Hi BitRecover, I am working as a system administrator with an IT company. Here we use On-Premises Exchange Server 2019 that has 10+ over 100 GB mailboxes and 20+ over 50 GB user mailboxes. Now management want to migrate over 50 GB or 100 GB users to Office 365 due to business requirements. I was recently connected to a software company that suggested multiple software to perform this task, but I don’t want to use multiple software to do this task. Kindly suggest to me a fully dedicated or customized single tool to migrate mailboxes over 100 GB to Office 365.

– Robert, System Administrator

#1 Step: Export PST File from Exchange Server

First, you need to export your mailbox data from Exchange Server in PST (Personal Storage Table) format. If you have already exported user mailbox data in PST format, then you can skip this step.

1. Go to Exchange Admin Center and choose Recipients >> Mailboxes >> More Options • • • to continue.
2. Thereafter, choose the Export to a PST file option from the dropdown.
   
3. Select a mailbox that has more than 50 GB size using the Browse button.
   
4. Choose one option from “Export only the contents of this mailbox or Export only the contents of this mailbox’s archive” according to your requirements. Press Next to continue.
   
5. Enter the universal naming convention (UNC) path and file name and click Next.
   
6. Enable “Send email to the mailbox below when the .pst file has been exported” and click on Browse to add notification recipients.
   
7. Finally, click on the Finish to complete this step.
   

Note: Thereafter, you will receive a notification when your export is ready in PST format.

#2 Step: Manage Mailbox Bigger Than 100 GB Before Migration

You need to manage PST files before beginning the process and see how you can make your mailbox more efficient and ready to reuse without showing any errors or warnings.

• Microsoft Outlook offers various options to reduce PST file size, you can use these options.
• This is also advisable to remove duplicate emails from PST file to avoid email clutter before starting the email migration process.
• You need to split PST file into smaller parts before migrating mailboxes over 50-100 GB to Office 365 to avoid stuck problems. (You can do this using above mentioned single software as shown in the upcoming section.)

#3 Step: Make Your Over 100 GB Mailbox Reusable

Large PST file become the reason for several problems like corruption, slow speed, quota space, etc. So, in this case, this is highly recommended to make your large mailbox reusable to avoid future problems.

1. Launch the above recommended tool and add large mailbox file using the Select Files or Select Folder option.
   
2. Select mailbox folders including all items and hit the Next button.
   
3. Choose PST as the saving option as shown in the screenshot.
   
4. Enable the Split PST File option and choose 20 GB Size.
   
5. Browse the Destination Path to store reusable PST files.
   
6. Press Convert to create 20 GB size PST files.
   
7. Last, the software will open the destination path so you can easily get the resultant files.

#4 Step: Ensure Enough Quota Space Is Available in Your Office 365

Now this is time to ensure that enough quota space is available or not in your Microsoft 365 account. You can follow below mentioned tips and tricks to ensure enough quota space:

1. Log in to your Office 365 account and choose Outlook from available Apps.
   
2. Click on Settings (Gear Icon) as shown in the below figure.
   
3. Select General >> Storage option.
   
4. Now you can see available and used storage space.
   

Note: Here, you can see enough storage quota space is not available so you can’t migrate over 100 GB users to Office 365. The upcoming section describes steps to get enough quota space.

#5 Step: Get Enough Quota Space in Your Office 365

This section describes the 2 different ways to increase Office 365 mailbox size to 100 GB. You can use any way according to your preferences:

Method 1: Enable In-Place Archive

You can enable in-place archive in Office 365 to get 50 GB to 1.5 TB extra space depending on your Office 365 subscription plan. You can use this in-place archive storage to store your large mailboxes.

1. Open the Exchange Admin Center (EAC).
2. Select Recipients options.
   
3. Choose the Mailboxes option from Recipients.
   
4. Select a user account according to your preferences.
   
5. After that, click the Username and choose Others.
   
6. Now select the Manage Mailbox Archive option.
   
7. Enable archive, give a name to the mailbox archive folder, and press Save.
   

Method 2: Upgrade Subscription Plan

1. Open Microsoft 365 Admin Center or you can directly visit https://admin.microsoft.com/.
2. Select the Billing option.
   
3. Afterward, choose Purchase Services >> Microsoft 365 option.
   
4. Select an Office 365 Enterprise E3 or E5 plan and click Details.
   
5. Choose license quantity and buy a subscription.
   

#6 Step: Migrate Mailboxes Over 100 GB to Office 365

This is the last step for completing the process to migrate over 50-100 GB users to Office 365. Now after creating reusable PST files, you may have 4-5 PST files with a maximum of 20 GB size. Now this is time to open PST file in Office 365 account, Let’s know the steps:

1. Start the software and choose one option for adding PST file(s) in the software panel.
   
2. Select Office 365 folders and click Next.
   
3. Choose Office 365 as a saving option.
   
4. Fill Office 365 login credentials, and enable one option from Export to primary and in-place archive mailbox according to your choice.
   
5. Click Connect to migrate mailbox over 100 GB to Office 365.
   

Conclusion

After completing above mentioned steps anyone can easily migrate mailbox over 100 GB to Office 365. You can see, we have completed the process to migrate mailbox bigger than 100 GB to Office 365 using a single software as we promised. If you have any questions or doubts about the query, then you can contact our technical support team. They will help you complete the process of migrating mailboxes over 50 GB to an Office 365 account.