How to modify email size limits for Microsoft 365 Group Mailboxes

In Microsoft 365, email accounts often have default size limits for both sending and receiving messages. While individual user mailboxes can have these limits adjusted through the Exchange Admin Center, modifying size restrictions for group mailboxes requires the use of PowerShell commands.

As an administrator, you can follow the steps below to change the email size limits for Microsoft 365 group mailboxes:

1. Run PowerShell as Administrator:

Open PowerShell with administrative privileges. This is essential for executing commands related to Microsoft 365.

Install-Module -Name ExchangeOnlineManagement
Set-ExecutionPolicy -ExecutionPolicy unrestricted
Import-Module ExchangeOnlineManagement
Connect-ExchangeOnline #（Sign in with administrator credentials）

2. Check Current Size Limits:

Before making any changes, it’s a good practice to view the current maximum send and receive sizes for the group mailbox.

Get-UnifiedGroup -Identity [email protected] | Format-List MaxSendSize,MaxReceiveSize

3. Modify Attachment Size Limits:

Adjust the maximum send and receive sizes for the group mailbox. In this example, both limits are set to 150 MB.

Set-UnifiedGroup -Identity [email protected] -MaxSendSize 150mb -MaxReceiveSize 150mb

By following these steps, administrators can successfully modify the email size limits for Microsoft 365 group mailboxes using PowerShell. It’s important to tailor the size limits according to organizational requirements and consider factors such as attachment sizes in emails.