Microsoft 365 mailbox usage reports in M365 Manager Plus

Microsoft 365's native mailbox usage report provides detailed information about each user mailbox in your Microsoft 365 tenant. It monitors and tracks mailbox size and quota for every user mailbox to help prevent any data loss.

When it comes to downloading usage reports, both Exchange Admin Centre and PowerShell have limited capabilities. While the former provides minimal information, the latter requires scripting.

M365 Manager Plus, a comprehensive Microsoft 365 usage reporting tool, allows you to automatically monitor users with just a few clicks. It gives information on email activity, active users count, storage quota, storage used, and much more.

With M365 Manager Plus, you can get complete real-time reporting on your organization's Exchange Online mailboxes. These reports can be scheduled to run at different intervals, emailed to administrators, or exported to CSV, XLSX, PDF, or HTML formats.

Microsoft 365 mailbox usage reports include:

• Daily Email Activities Count by Type
• Daily Unique User Count by Email Activity
• Daily Outlook User Activity
• Daily Active Mailbox Count
• Daily Mailbox Count by Storage Quota Status
• Daily Mailbox Storage Used
• Daily Unique User Count by Email App
• Last Outlook User Activity by App
• Outlook Unique User Count by Version

Daily Email Activities Count by Type

Gives the total count of every day email activities by type — read, receive, and send.

• Read action: A count of the number of times a user has read emails in the mailbox. If an email is opened multiple times, it will count each as a separate read activity.
• Receive action: A count of the number of times a user has received mails in the mailbox.
• Send action: A count of the number of times a user performed a send mail action in the mailbox.

Daily Unique User Count by Email Activity

Gives the total count of daily email activities performed by unique users in the Exchange Online tenant. This count only includes the number of users who perform any action, not the number of actions performed by those users.

Daily Outlook User Activity

Gives details of each day's Outlook email activities performed by users. Apart from the read, receive, and send actions, you can also track the following details:

• Deleted: Shows a list of mailboxes that are currently deleted.
• Last activity date: Shows the last time a user performed a read or send email activity.
• Deleted date: Shows the date on which a mailbox was deleted.

Daily Active Mailbox Count

Lists the count of mailboxes that were active on a particular day, and presents a comparison to the total number of mailboxes.

Daily Mailbox Count by Storage Quota Status

Shows the number of mailboxes that have crossed the specified storage quota limit in a given day. Storage quotas let you control the size of mailboxes, and you can configure notifications to be automatically sent to a user when they approach the storage quota. This report will give you insights into the following data that can be used to optimize the mailbox size and quota.

• Warning issued: Shows the list of mailboxes to which a warning message was sent to the user due to either reaching or exceeding the quota specified.
• Send/receive prohibited: Shows the list of mailboxes that were prohibited from sending or receiving mails due to an exceeded storage quota.
• Send prohibited: Shows the list of mailboxes that were prohibited from send action due to an exceeded storage quota.
• Good (under limits): Shows the list of active mailboxes that are within the storage quota limit.

Daily Mailbox Storage Used

Provides the total utilization of storage space used by all mailboxes in your organization every day.

Daily Unique User Count by Email App

Shows the number of unique users every day for each email application, such as Mail for iOS, Outlook for Windows, Outlook for mobile, Outlook for macOS, and other mobile apps.

Last Outlook User Activity by App

Shows the Outlook user activity for all the users in your organization for each Outlook application, such as Outlook for macOS, Outlook for Windows, and Outlook for mobile.

Outlook Unique User Count by Version

Lists the unique user count by the version of Outlook used such as Outlook 2007, Outlook 2010, Outlook 2013, and Outlook 2016.