Software Needed for import: 

https://aka.ms/downloadazcopy (AzCopy, Move PST to Azure Blob) 

https://go.microsoft.com/fwlink/p/?LinkId=544717 (CSV Mapping File) 

1. In the Source Tenancy go to https://admin.microsoft.com/AdminPortal/Home#/reportsUsage/MailboxUsage and set the filter to storage : 
2. Install the Software on a device with enough storage to hold the mailboxes 
3. Open the PST migration tool 
4. Add Migration account to 365 as a Global Administrator (Needs to have and exchange License and a .onmicrosoft.com UPN) 
5. Open Exchange PowerShell 
6. Edit the account in this command and run it in the PowerShell (Make sure the mailbox has created for the migration account)  

   Get-Mailbox -ResultSize unlimited | Add-MailboxPermission -User "MigrationAccount@***.onmicrosoft.com" -AccessRights FullAccess -InheritanceType all 

   
   

7. Edit the CSV Path and run this command  

   Get-Mailbox -ResultSize Unlimited | Select UserPrincipalName,DisplayName |Export-csv -Path C:\Temp\Export.csv  

   
   

8. Wait a few hours for permissions to propagate 

9. In PST export add the migration account:
    

10. Under “Export PST” Select All mailboxes and the storage locations for the PST (untick Discovery Search Mailbox and the Migration account) Select User Principal Name for the File Name 

11. On the next page click Export. This will export the PSTs of the accounts to the Local Storage 

12. When the Export is complete delete the migration account from Office 365

IMPORT Mailboxes 

1. In the Exchange Admin (Central Tenancy) Add your user to Export/Import PST Mailboxes: 
    

2. Wait for up to 24 hours for the permissions to update and then go to https://protection.office.com/import 

3. Create new Import Job 

4. Click through the wizard (Name is lowercase and no spaces & chose Upload your data)

5. Copy SAS URL to a text document for later 

6. Open Azure copy and use this command to copy the PSTs to the Azure Blob  

   azcopy.exe /source:”Location of downloaded PSTs” /Dest:”SAS URL” /V:”Log File Location” /Y

   
   

7. Edit the CSV Location and the ABP to the school code 
   

   Get-Mailbox -Filter {(UserPrincipalName -like "*onmicrosoft.com") -and (CustomAttribute15 -eq "AVA_ABP")} | Select UserPrincipalName,GUID | export-csv C:\Temp\365.csv  

   
   

8. Copy The user Principal Name from the Export csv in step 7 of the export to the NAME column of the mapping document (you need to add .PST to the end of all CONCATENATE will work the best – Copy the contents of the column and paste over the top selecting “Paste Values” 

9. Take the GUID from the export in Step 7 and match the UPN to the GUID in the Mapping CSV 

10. Set the “workload” column to Exchange for all mailboxes and Is Archive to False. The Target Root Folder is / 

11. Upload the CSV to the PST import in the compliance centre and Validate it  

12. Office will now validate the files; this may take some time (365 will email you when it is done)

    

13. When done click “Ready to Import to Office 365” 

14. Select NO for data Filtering and click import data 

15. The import will take ages 

16. When the import is done all the mail has migrated 

Important Note – All mailbox permissions will need to be recreated in the new tenant   

2nd Method

This method includes calendars in the PST but requires the PSTs to be "cleaned" as after export, the "Inbox" folder is put into a "Top of information store" folder. 

Guide used

Export

Ediscovery Manager role required – enables export

1. Compliance center, new search, select users, export to to PST.
2. In the Security and Compliance center go to Search, Content Search: 
    
   Create a new search
   
   Edit the locations
   
   Then select the mailboxes you want to export, or just select all
   

   Back on the search page, click on the newly created search and wait for the results to finish (status is at the bottom of the window), once finished click export results
   Review the options then click Export (All items and one PST for each mailbox is fine)
   
   You must use Edge or internet explorer for this step, because of course you do

"Clean" PSTs

Now we need to clean the PSTs, this method is only really suitable for relatively low amounts of PSTs. If you have more than said "relatively low amounts" then either get the staff to do this bit themselves or use method 1.

All you have to do is open the PST one by one into Outlook and move the folders back into their correct order.

This is what they look like fresh off the import wagon:

This is what they should look like:

note, if dragging and dropping doesnt change the order, try right click moving.