Learn How to Increase Mailbox Size in Office 365 – Top 6 Ways
Summary: In this article, you will learn how to increase mailbox size in Office 365. Microsoft 365 is a complete productive suite that offers a wide range of features to enhance your working efficiency. One of the key aspects of Microsoft Office 365 is email used in day-to-day life. However, as the business grows and the use of emails increases. You notice that you need more storage in the Office 365 mailbox this writing is for you. It helps you to know how to increase the mailbox size in Office 365. And get more working space for your tasks.
Table of Contents,
Office 365 consists of different subscription plans that come across different storage spaces. It depends on the requirements of the users and which plan is suitable for their organization. If the use of a mailbox increases, the storage is not sufficient for the user as emails come with different attachments.
However, by resolving this problem you can work productively as you have an ample amount of storage. That’s why you must know how to increase mailbox size in Office 365.
Exploring the Size of Mailbox in Microsoft Office 365
The size of Microsoft 365 or Office 365 depends on two major factors. The first one is the type of mailbox you are using and another one is the subscription plan purchased by you. When choosing a subscription, it completely depends on the requirement of the organization that you need to purchase a plan sufficient for your organization. But after some time due to bulk email, the storage ran out.
In general, the default size of the Office 365 subscription mailbox is 50 GB, while top subscriptions have 100 GB of space. So let’s explore the size of mailboxes along with different subscription plans with the help of the table given below.

This table shows different subscription plan sizes.
Mailbox Size After Updation in Microsoft 365
If you assigned Microsoft 365 E3 OR E5 plan, the user mailboxes’ size can be increased to 100 GB. The F3 license does not come with an archive mailbox & has storage of 2 GB only. Every subscription has a public folder mailbox of a 100GB limit. However, the shared mailbox comes across a 50 GB limit size and does not require any license but if you assign any plan to it, they store up to 100 GB. You can extend the storage space of Users and shared mailboxes by archiving which has 50 GB of space to each mailbox. You can make an archive mailbox unlimited by assigning Exchange Online plan 1 or 2 along with Exchange Online Archiving add-on license.
Note: After November 1, 2021, there is a limit on auto-expanding of an archive mailbox. The max size is 1.5 TB at the rate of 1GB per day. Microsoft 365 removed unlimited words from their documentation.
Hope you get some sort of idea about the different sizes of mailboxes in Microsoft 365 and Office 365.
Steps to Check Office 365 Mailbox Size
If you are using the mailbox of Office 365. You must know how to check the Office 365 mailbox size. Therefore, you are aware of how much storage is used by users so that you can increase the mailbox size in Office 365. However, there are two ways to check the Office 365 Mailbox Size listed below.
- By using Outlook Online
- By using the Exchange admin center
For checking the Office 365 mailbox size by using Outlook online you need to follow these steps.
Step 1. First, visit the website of Outlook with your local browser.
Step 2. Login to Outlook online with the valid Microsoft credential IDs.
Step 3. Navigate to the “Settings” option present at the top.
Step 4. Go to the “General” option and then select “Storage.”
Here, With the above-mentioned steps, you can check the size of the mailbox and each subfolder. If mailboxes are about to full you need to know how to increase mailbox size in Office 365. One more method is mentioned below.
Steps to check Office 365 mailbox size by using the Exchange admin center are as follows.
Step 1. Go to the Exchange Admin Center with the browser.
Step 2. Log in to the Exchange Admin Center with your credential IDs.
Step 3. Go to “Recipient” then select “Mailboxes” where the list of mailboxes of your organization appears.
Step 4. Click on the account you want to check, and a pop-up window appear showing their information.
How to Increase Mailbox Size in Office 365?
There are several reasons including increased storage requirements, data loss avoidance, improved productivity of organization & compliance so you need to increase the mailbox size in Office 365. The different ways used to increase the mailbox size are,
- Way 1. Deleting Unuseful Data
- Way 2. Upgrade to Another Subscription Plan
- Way 3. Configure the Archive Mailbox
- Way 4. Make Use of The Retention Policy
- Way 5. Setting Up Using PowerShell
- Way 6. Migrate to Another Platform
So let’s discuss each of them one by one in brief.
Way 1. Deleting Unuseful Data
This is one of the easiest ways, used by every second person that does not affect the cost of the user. Just you need time to delete data since you need to check and filter the unuseful emails present in the mailbox. This helps you to clean & manage your mailbox to free up space. You need to regularly clean your mailbox to maintain it. However, it is a time-consuming method if you have the appropriate time you can perform it otherwise.
Way 2. Upgrade to Another Subscription Plan
Yes, it is much simpler if you are running out of storage you can upgrade your subscription plan to Office 365. Buying a higher Office plan like E3 or E5 with high storage can increase the mailbox space. However, it comes with the additional cost of purchasing a new plan and then you need to migrate the files from one plan to another.
Way 3. Configure the Archive Mailbox
An effective way to increase the mailbox size in Office 365 is by enabling the archive mailbox. You can free your primary mailbox by loading them into an archive mailbox. You must have Exchange Online plan one or plan two along with an Exchange Online Archiving add-on license to enable it. Otherwise, you are not able to add it to your mailbox.
- Basic Plan of 50 GB Archive – You can enable an additional 50GB storage space for your mailboxes.
- Auto-Expantion Archive Plan comes with E3 or E5 plans – In this, the user gets 50 GB of additional storage. After that auto expansion of 1GB daily until the user gets 1.5 TB storage.
You can find more information about the archive mailbox in the article.
Hope with the above method you may learn how to increase mailbox size in Office 365. If not there are more methods mentioned below.
Way 4. Make Use of The Retention Policy
Retention Policy in Office 365 is used to manage how long emails and other data are stored. It helps to automatically delete or archive data based on the hold applied to it. Helps to reduce confusion by organizing mailboxes. And also manages storage efficiency and compliance. You need to configure automatic deletion or archiving of emails based on requirements and other criteria.
Way 5. Setting Up Using PowerShell
Making use of Microsoft 365 PowerShell is a good practice. However, You can set limits for a single user as well as multiple users using power shell commands. By configuring the size and limits of mailboxes one user can use storage. Power Shell is present on your system.
Note: When using PowerShell run it as the Administrator.
Maybe you can get some clear pictures of how to increase mailbox size in Office 365. If you want to ease your work you may use any professional software. Read the last way for more information.
Way 6. Migrate to Another Platform
If the above ways are not working the last way you need to apply i.e. migrate your subscription plan to another platform or plan. However, Microsoft 365 does not provide any solution to migrate data. You need to make use of automated software present in the market. One of the best software is the Migrator Wizard Office 365 Migration Tool.
This tool comes with unique features that are listed below as follows.
- Delta Migration for the newly arrived data.
- Re-run the migration if the item gets skipped due to somehow.
- Perform multiple-user or single-user account migration.
- You can stop or start migration according to your ease.
Want to know more about migration read this how to Transfer Office 365 Mailbox to Another Account?
Finishing Up
In general, If we talk about the mailbox which is an essential part of any organization for sending and receiving emails. Since your mailbox is running out of storage you can miss important mail causing some loss. If dealing with the same problem. Therefore, this article is beneficial for you if you want to increase the size of your mailbox and know Moreover, you must know how to increase mailbox size in Office 365. Additionally, there are many different ways mentioned above for the ease of the user.