How do I migrate large mail items to Office 365?
Answer:
Important: The steps in this article require that you connect to Office 365 with Windows PowerShell. Refer to the Connect to Office 365 PowerShell article from Microsoft for detailed steps on how to connect to Office 365 using Windows PowerShell.
To migrate items to Office 365 that are larger than the EWS defaults, you will need to run the following PowerShell scripts.
First, you should run this script against your Office 365 environment to determine what your current settings are:
Get-Mailbox testuser01 | fl mailboxplan,maxsendsize,maxreceivesize
Notes:
- The user can be any standard user on Office 365 that has a SKU assigned that contains a mailbox license.
- It should be a user whose settings have not been previously modified.
Example results:
MailboxPlan: ExchangeOnlineEnterprise-4b910ff9-8b91-4f2e-960c-302a90c95668
MaxSendSize: 35 MB (36,700,160 bytes)
MaxReceiveSize: 36 MB (37,748,736 bytes)
Next, run this script against your Office 365 environment to set the Mailbox Plan, the Max Send Size and the Max Receive Size:
Get-MailboxPlan | Set-MailboxPlan -MaxSendSize 150MB -MaxReceiveSize 150MB
Note: New users created after you change the mailbox plan will have 150MB as the max send and receive size. However, the current user will still have 35MB. To increase the limit for all users you can run:
Get-Mailbox | Set-Mailbox -MaxReceiveSize 150MB -MaxSendSize 150MB
The example below shows how you can validate that the new limits are applied:
PS C:\Windows\system32> Get-Mailbox testuser01 | fl mailboxplan,maxsendsize,maxreceivesize
MailboxPlan: ExchangeOnlineEnterprise-4e910ff9-8b91-4f2e-960c-302a90c65668
MaxSendSize: 150 MB (36,700,160 bytes)
MaxReceiveSize: 150 MB (37,748,736 bytes)
Comments
4 comments
You can change the default for an organization by adjusting the default message size restriction. In the Exchange admin center Simply select recipients > mailboxes then click “. . .” and select Set default message size restrictions.
You can then specify the maximum message size for new mailboxes (only for those you create in the future).
For existing users...
To edit multiple mailboxes select recipients > mailboxes and select multiple mailboxes. Then from the Bulk Edit pane under Message Size Restrictions select Update.
You can customize a single mailbox by selecting recipients > mailboxes and then select a user’s mailbox. Click the edit icon , then under Message Size Restrictions, click View details and then specify the maximum message size.
Credit due to: https://blogs.office.com/en-us/2015/04/15/office-365-now-supports-larger-email-messages-up-to-150-mb/
After following the guide - "Connect to Office 365 PowerShell" from Microsoft listed in this KB article, you need to follow additional guide - "Connect to Exchange Online PowerShell" to be able to execute those PS commands, otherwise you will get errors from PowerShell such as "The term 'Get-Mailbox' is not recognized as the name of a cmdlet, function, script file, or operable".
Life saver Georgiy Frolov !
Gregoriy FTW.
Thank you.
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