Microsoft announced a few months ago that the mailbox size limit would be doubled for all new and existing Office 365 customers by the end of November 2013. Standard mailboxes would be increased from 25 to 50 GBs while shared mailboxes would be increased from 5 to 10 GBs. However, it’s already the last day of November and I noticed that none of my client’s mailbox size limits had been increased. It turns out that Microsoft is in no hurry to roll this out and is hoping to upgrade all existing customers by the end of the year. You can, however, manually increase the size limit on a mailbox by using the following PowerShell commands:
For user mailboxes:
Get-Mailbox -RecipientTypeDetails UserMailbox | Set-Mailbox -ProhibitSendQuota 49.75GB -ProhibitSendReceiveQuota 50GB -IssueWarningQuota 49.50GB
For shared mailboxes:
Get-Mailbox -RecipientTypeDetails SharedMailbox | Set-Mailbox -ProhibitSendQuota 9.75GB -ProhibitSendReceiveQuota 10GB -IssueWarningQuota 9.50GB
The Microsoft support technician I spoke to today assured me that manually increasing the size limit shouldn’t create any issues. So you can either continue waiting for Microsoft to get around to upgrading your mailboxes or you can try using the PowerShell scripts provided above.