Organizations look for a Microsoft 365 mailbox usage report when they have difficulty managing their mailbox storage. Quota warnings may be sent to users, increasing the amount of money spent on storage by an administrator, or email migration may show that certain user mailboxes are much larger than anticipated. In most cases, the IT group would like to be able to quickly identify what user account is consuming the most mailbox data and if the user has reached their allocated limit.
Organizations are continuing to grow their mailbox sizes as they become more dependent on Microsoft 365 and Exchange Online because of emails, attachments, shared mailboxes, and archived data. Without monitoring mailbox size frequently, oversized mailboxes will negatively impact storage planning, compliance efforts, migration projects, and overall email management.
The Microsoft 365 Mailbox Usage report will allow administrators to assess mailbox consumption, size, email activity, item count, and quota for their organization. By reviewing the reports on a regular basis, organizations can be proactive with their mailbox growth and avoid unexpected storage issues.
What is a Microsoft 365 Mailbox Usage Report?
Microsoft 365 Mailbox Usage Reports is a built-in reporting tool to help Administrators track:
- Mailbox sizes per user,
- Storage used,
- Mailbox quotas,
- Email activity,
- Item counts,
- Archived Mailbox usage, and
- Trends in Storage for the Organization.
The Microsoft 365 Mailbox Usage Report gives administrators a high-level overview of Exchange Online and which mailboxes are consuming too much storage or need to be investigated.
Why Do Administrators Need an Office 365 Mailbox Usage Report?
Many organizations ignore mailbox storage until it becomes a problem. For this reason, many organizations look to obtain a Microsoft 365 mailbox usage report as a way to:
- Identifying users that are close to exceeding their mailbox limits
- Minimizing storage issues
- Preparing to migrate to Microsoft 365
- Fulfilling compliance obligations
- Tracking storage growth trends
- Optimizing Microsoft 365 licensing
- Improving Exchange Online performance.
When an organization does not have access to Microsoft 365 mailbox usage reports, they are typically forced to react to issues associated with mailbox storage rather than preventing the issues from occurring.
What Information Does a Microsoft 365 Mailbox Usage Report Show?
Valuable statistics from mailboxes are included in this report for administrators’ use when assessing tenant storage usage. Typically, the following information is found in the report’s data:
- User Name
- Email Address
- Size of mailbox
- Total storage needed to store mailbox
- Percent of quota being used
- Date of last activity in the mailbox
- Number of items in the mailbox
- Status of archive mailbox
- Allocation info for storage
The metrics in the report allow you to get a better sense of how your mailbox is functioning and how it is being used compared to other mailboxes on the tenant.
How to Check Mailbox Usage in Microsoft 365
There are multiple methods to create a mailbox usage report in Microsoft 365.
Method 1: Use the Microsoft 365 Admin Center
Most administrator’s prefer to use this method because it is fairly easy to follow.
To do this, follow the steps below:
- Login to your Microsoft 365 admin center.
- Once you are logged in, click on the Reports option from the left pane.
- Once you are in the Report area click on Usage Reports.
- Next click on Mailbox Usage.
- Once you are on this page you can then view the statistics for each mailbox.
- If you need the mailbox usage report, you can export it directly from this page.
This report will provide you with a complete summary of how much storage is utilized by each user within your organization.
Method 2: Exchange Online PowerShell
PowerShell allows for more sophisticated forms of reporting than other forms of business software, and it is therefore widely used in organizations where there is a requirement for high-quality reports.
Exchange Online / Connect to Exchange Online
Connect-ExchangeOnline
Retrieve Statistics for Specific Users
Get-MailboxStatistics -identity [email protected]
Generate a Report for All Mailboxes
Get-Mailbox -ResultSize Unlimited Get-MailboxStatistics Select DisplayName, TotalItems, ItemCount
With this process, administrators can generate individualized custom reports and perform automated mailbox monitoring processes.
Common Storage Issues Revealed by Microsoft 365 Mailbox Usage Report
Reports detailing user mailbox sizes can expose issues hidden in an organization.
- Overlarge user mailboxes
Many users will store hundreds of emails with large attachments for many years, leading to an extremely large mailbox size. - Inactive user mailboxes
Mailboxes from inactive employees or inactive mailboxes take up valuable space while not being actively used. - The rapid growth of shared mailboxes
Departmental mailboxes are usually large because many users contribute to them, leading to their expansion more quickly than other types of mailboxes. - The presence of large attachments
Attachments to emails are one of the major contributors to large mailbox sizes. - Poor utilization of archive mailboxes
Companies that do not manage their archives properly will have increasing pressure on their storage systems.
Best Practices for Managing Microsoft 365 Mailbox Storage Report
Creating reports is just the beginning. Organizations must also apply strategies for managing their data’s storage space.
- Monitoring your mailbox use on a monthly basis
It is vital to generate monthly reports to help identify any potential storage problems prior storing. - Use Online Archive
Storing older emails into archive mailboxes will greatly reduce pressure on the main mailbox. - Use Retention Policies
Using retention policies will help automate the cleanup process in your mailbox and manage the mailbox storage. - Review of Resources Email Mailboxes
Often shared mailboxes become overloaded with data causing a major storage issue and should be regularly reviewed. - User Education
A significant decrease in mailbox increases can be achieved through teaching users how to manage attachments and retain old emails.
Why Mailbox Reporting Matters Before Backup and Migration Projects
Mailbox usage reports in Microsoft 365 are extremely valuable for an organization when preparing for the following activities:
- Migrate to Microsoft 365
- Perform a tenant-to-tenant migration
- Perform a compliance audit
- Perform an email backup project
- Engage in storage optimization
The information provided by a mailbox size report allows administrators to create accurate estimates of required project timelines and resources by providing insight into the estimated size of the mailboxes they will be dealing with when implementing these activities.
During an audit of mailboxes, some organizations find critical business data contained in a relatively small number of large mailboxes. As a result, many administrators will combine mailbox reporting with backup strategies to ensure critical business data is locked down. SysTools Office 365 Backup Tool solutions for creating secure backups of mailboxes (including emails and attachments) prior to any large-scale migration, compliance audit or storage management attempts are widely used for this reason.
Limitations of Native Microsoft 365 Mailbox Reporting
There could be numerous challenges that administrators face, despite Microsoft providing useful native reports. These limitations include:
- Limited reporting on historical data
- Manual export of reports
- No advanced reporting features
- Limited visibility into historical trend data
- Use of PowerShell for detailed reporting
Most organizations with large numbers of Microsoft 365 users have a secondary source for management and backup of their Microsoft 365 usage.
Frequently Asked Questions
Q 1: How can I see how much space I have left on my Microsoft 365 Account?
The Microsoft 365 admin center, The Exchange Admin Center, and The Exchange Online PowerShell all allow you to see the size of your mailbox.
Q 2: Can I download a Microsoft 365 account usage report?
Microsoft allows administrators to export usage reports for the purpose of further review only in a CSV format.
Q 3: What is a good practice for reviewing mailbox use reports?
Most companies will review their Mailbox usage on a monthly basis, while large businesses will do so on a bi-weekly basis.
Q 4: Is the size of my mailbox different than the number of items in it?
Yes, the size of your mailbox is the space that the email has occupied in your mailbox as it has been sent for use, while usage reports contain additional data about the items in your mailbox such as activity, how many items you have, how much of your quota you have used, and what type of items you have created.
Q 5: Is monitoring my mailbox usage important?
Regular mailbox usage monitoring can help you avoid running into quota issues, help with planning for additional storage, support compliance efforts and help to minimize your Microsoft 365 costs.
Conclusion
A Microsoft 365 Mailbox Usage Report is one of the most critical tools available for Exchange Online storage management. This tool allows for monitoring mailbox size, identifying historical trends in mailbox growth, detecting oversized mailboxes, and enabling administrators to optimize storage utilization throughout the organization.
Regardless of whether you are utilizing the Microsoft 365 Administration Panel or PowerShell, reviewing mailbox usage reports on a regular basis allows for proactive management of the mailbox, as well as better storage planning. Many organizations wishing to have long-term protection of their mailboxes may want to consider using mailbox reporting in conjunction with dedicated backup solutions to effectively protect their Microsoft 365 data and maintain business continuity.
