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ADJUSTING MY MAILBOX QUOTA ONLINE

Michael Cruz 0 Reputation points
2026-04-27T16:47:33.8733333+00:00

HOW DO I ADJUST TMY MAILBOX QUOTA ONLINE SO I CAN USE THE FULL 100mb IN MY INBOX

Exchange | Exchange Server | Management
Exchange | Exchange Server | Management

The administration and maintenance of Microsoft Exchange Server to ensure secure, reliable, and efficient email and collaboration services across an organization.

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  1. Q&A Assist
    2026-04-27T16:47:43.6366667+00:00
    AI generated content. This question contains an answer created with AI from Q&A Assist. Learn more

    Mailbox quota cannot be increased by end users. To use the full quota allowed by the license (for example, up to 100 GB in Exchange Online), an Exchange or Microsoft 365 administrator must configure the mailbox settings.

    For Exchange Online mailboxes, an admin can:

    1. Connect to Exchange Online PowerShell.
    2. Run Set-Mailbox to set custom quotas (or to raise them up to the licensed maximum), for example: 
         Set-Mailbox <UserID> -ProhibitSendQuota 99GB -ProhibitSendReceiveQuota 100GB -IssueWarningQuota 98GB
      Replace <UserID> with the mailbox UPN or email address.
    3. Verify the quotas: 
         Get-Mailbox <UserID> | Select *quota*

    If a smaller, explicit quota was set earlier, it will not automatically increase when a larger license is assigned. In that case, the admin must manually update the quotas as above. If needed, ensure UseDatabaseQuotaDefaults is set to $false so the custom values are honored:

    Set-Mailbox -Identity <UserID> -UseDatabaseQuotaDefaults:$false

    End users who are not administrators cannot change these quota values themselves; they must contact their organization’s IT or Exchange administrator to adjust the mailbox quota.

    References: