skip to Main Content

Get mailbox database size and white space

What is the best way to get information about the mailbox database size? Why would you need to know the database size and white space of a database? What is the white space in a mailbox database? In this article, you will learn step by step how to retrieve the information. First, it’s important to understand what the available new mailbox (white) space is.

What is the available new mailbox (white) space?

You already know what the database size is. The more mailboxes that contain email in a database, the more the database will grow. Right? Unfortunately, that is not the correct answer. The mailbox database will increase only in database size if there is no available new mailbox space available.

The database size is the size that is using the disk volume. If you have a 100GB mailbox database size, that means it will show as 100GB in size on the disk. Now, what is the available new mailbox space? Let’s say we are going to remove several mailboxes from the database or users are deleting emails from their mailbox. The database will not shrink in size. The removed data will be available for new mailbox space.

Example: If the database is 100GB in size and we remove mailboxes that contain 20GB in size. It does not mean that we have an 80GB database in size on the disk. The database will stay on 100GB. The 20GB will be the available new mailbox space. When we start creating new mailboxes, the mailboxes will start growing. That is because the users are sending and receiving emails. This will first use the 20GB space, the available new mailbox space. If the users in the database are using more then 20GB, the database will get higher then 100GB. This means that the database on disk size will be higher than 100GB.

Get mailbox database size and available new mailbox space

We are going to make use of the Get-MailboxDatabase cmdlet. Run Exchange Management Shell as administrator. Run the following command.

Sort mailbox database size on available new mailbox space

We like to sort the output on the available white space.

It will look better if the statistics only show size in GB. For example, if you want to place it in a document.

Clear the available white space in the mailbox database

You like to clear the available white space because it’s taking to much space on the disk. We recommend the following:

  1. Create a new mailbox database in Exchange Server
  2. Move all mailboxes to the new database
  3. Remove old database in Exchange Server


In this article, you learned how to get mailbox database size and white space with PowerShell. It’s good to know how to find the size of the mailbox database and the mailbox available space. I hope that this article was informative to you.

Did you enjoy this article? You may like Pause all mailbox move request in Exchange. Don’t forget to follow us and share this article.



ALI TAJRAN is a passionate IT Architect and IT Consultant. His specialism is designing and building complex enterprise environments. He started Information Technology at a very young age, and his goal is to teach and inspire others. Connect with ALI TAJRAN on social media. Read more »

This Post Has 0 Comments

Leave a Reply

Your email address will not be published. Required fields are marked *

Back To Top