Use the Get-MailboxStatistics PowerShell CmdLet to retrieve mailbox size, item count, and more from a single or multiple mailboxes.
Get mailbox size of all users in Exchange with PowerShell - ALI TAJRAN
How to Increase Mailbox Size in Office 365 Exchange Online
Export Office 365 Mailbox Size Report Using PowerShell
Find Mail Box Size Office 365 Powershell & Expoert csv
Working with Archive Policies in Office 365 and SkyKick - GCIT
Get mailbox size of all users in Exchange with PowerShell - ALI TAJRAN
Check Office 365 Mailbox Size - Active Directory Pro
Find Office 365 Mailbox Size With PowerShell
PowerShell Script List Mailbox Size for All Users - IT World, Technology Site, Exchange, system, office 365, vmware, veeam, azure, Windows Server
Microsoft 365: List User Mailboxes sorted by Mailbox Size –