FAQ about importing PST files

This article is for administrators. Do you want to import PST files to your own mailbox? See Import email, contacts, and calendar from an Outlook .pst file

Here are some frequently asked questions about using the Office 365 Import Service to bulk-import PST files to Microsoft 365 mailboxes. For more information about how to import PST files, see Learn about importing PST files to Office 365.

Using network upload to import PST files

For step-by-step instructions, see Use network upload to import PST files to Office 365.

What permissions are required to create import jobs in the Office 365 Import Service?

You have to be assigned the Mailbox Import Export role in Exchange Online to create import jobs in the Microsoft Purview compliance portal and import PST files to user mailboxes. By default, this role isn't assigned to any role group in Exchange Online. You can add the Mailbox Import Export role to the Organization Management role group. Or you can create a new role group, assign the Mailbox Import Export role, and then add yourself or other users as a member. For more information, see the "Add a role to a role group" or the "Create a role group" sections in Manage role groups in Exchange Online.

In addition to the Mailbox Import Export role, you also have to be assigned the Mail Recipients role in Exchange Online. By default, this role is assigned to the Organization Management and Recipient Management roles groups in Exchange Online.

Tip

Consider creating a new role group in Exchange Online that's specifically intended for importing PST files to Office 365. For the minimum level of privileges required to import PST files, assign the Mailbox Import Export and Mail Recipients roles to the new role group, and then add members.

Where is network upload available?

Network upload is currently available in these regions: United States, Canada, Brazil, the United Kingdom, France, Germany, Switzerland, Norway, Europe, India, East Asia, Southeast Asia, Japan, Republic of Korea, Australia, and United Arab Emirates (UAE). Network upload will be available in more regions in the future.

What is the pricing for importing PST files by using network upload?

Using network upload to import PST files is free.

This also means that after PST files are deleted from the Azure Storage area, they're no longer displayed in the list of files for a completed import job in the Microsoft 365 admin center. Although an import job might still be listed on the Import data to Office 365 page, the list of PST files might be empty when you view the details of older import jobs.

What version of the PST file format is supported for importing to Office 365?

There are two versions of the PST file format: ANSI and Unicode. We recommend importing files that use the Unicode PST file format. However, files that use the ANSI PST file format, such as those for languages that use a double-byte character set (DBCS), can also be imported to Office 365. For more information about importing ANSI PST files, see Step 4 in Use network upload to import your organization's PST files to Office 365.

Additionally, PST files from Outlook 2007 and later versions can be imported to Office 365.

After I upload my PST files to the Azure Storage area, how long are they kept in Azure before they're deleted?

When you use the network upload method to import PST files, you upload them to an Azure blob container named ingestiondata. If there are no import jobs in progress on the Import PST files page in the compliance portal), then all PST files in the ingestiondata container in Azure are deleted 30 days after the most recent import job was created in the compliance portal. That also means you have to create a new import job in the compliance portal (described in Step 5 in the network upload instructions) within 30 days of uploading PST files to Azure.

This also means that after PST files are deleted from the Azure Storage area, they're no longer displayed in the list of files for a completed import job in the compliance portal. Although an import job might still be listed on the Import PST files page in the compliance portal, the list of PST files might be empty when you view the details of older import jobs.

How long does it take to import a PST file to a mailbox?

It depends on the capacity of your network, but it typically takes several hours for each terabyte (TB) of data to be uploaded to the Azure Storage area for your organization. After the PST files are copied to the Azure Storage area, a PST file is imported to a Microsoft 365 mailbox at a rate of approximately 24 GB per day*. If this rate doesn't meet your needs, you might consider other methods for migrating email data to Office 365. For more information, see Ways to migrate multiple email accounts to Office 365.

* This rate is not guaranteed. Server workload and transient performance issues might decrease this rate.

If different PST files are imported to different target mailboxes, the import process occurs in parallel; in other words, each PST/mailbox pair is imported simultaneously. If multiple PST files are imported to the same mailbox, they will be imported sequentially (one at a time), not simultaneously.

How does the PST import process handle duplicate email items?

The PST import process checks for duplicate items and doesn't copy the items from a PST file to the mailbox or archive if a matching item exists in the target folder in the target mailbox or target archive. If you reimport the same PST file and specify a different target folder (using the TargetRootFolder property in the PST import mapping file) than the one you specified in a previous import job, all items in the PST file will be reimported.

Is there a message size limit when importing PST files?

Yes. If a PST file contains a mailbox item that is larger than 150 MB, the item will be skipped and not imported during the import process. Items larger than 150 MB aren't imported because 150 MB is the message size limit in Exchange Online. For more information, see Message limits in Exchange Online.

Are message properties, such as when the message was sent or received, the list of recipients and other properties, preserved when PST files are imported to a Microsoft 365 mailbox?

Yes. The original message metadata isn't changed during the import process.

Is there a limit to the number of levels in a folder hierarchy for a PST file that I want to import to a mailbox?

Yes. You can't import a PST file that has 300 or more levels of nested folders.

Can I use network upload to import PST files to an inactive mailbox in Office 365?

Yes, this capability is now available.

Can I use network upload to import PST files to an online archive mailbox in an Exchange hybrid deployment?

Yes, this capability is now available.

Can I use network upload to import PST files to public folders in Exchange Online?

No, you can't import PST files to public folders.

Are there any screen resolution requirements when I create a network upload import job?

If the screen resolution on your local computer is set to 1366 x 768, you may have issues creating an import job. If this is the case, we recommend that you change the screen resolution to a different setting and then create a new import job. We're working to fix this issue.

Using drive shipping to import PST files

For step-by-step instructions, see Use drive shipping to import PST files to Office 365.

What permissions are required to create import jobs in the Office 365 Import Service?

You have to be assigned the Mailbox Import Export role in Exchange Online to create import jobs in the compliance portal and import PST files to user mailboxes. By default, this role isn't assigned to any role group in Exchange Online. You can add the Mailbox Import Export role to the Organization Management role group. Or you can create a new role group, assign the Mailbox Import Export role, and then add yourself or other users as a member. For more information, see the "Add a role to a role group" or the "Create a role group" sections in Manage role groups in Exchange Online.

In addition to the Mailbox Import Export role, you also have to be assigned the Mail Recipients role in Exchange Online. By default, this role is assigned to the Organization Management and Recipient Management roles groups in Exchange Online.

Tip

Consider creating a new role group in Exchange Online that's specifically intended for importing PST files to Office 365. For the minimum level of privileges required to import PST files, assign the Mailbox Import Export and Mail Recipients roles to the new role group, and then add members.

Where is drive shipping available?

Drive shipping is currently available in the United States, Canada, Brazil, the United Kingdom, Europe, India, East Asia, Southeast Asia, Japan, Republic of Korea, and Australia. Drive shipping will be available in more regions in the future.

Note

At this time, drive shipping to import PST files is not available in Germany and Switzerland. This FAQ will be updated when drive shipping is available in these countries.

What commercial licensing agreements support drive shipping?

Drive shipping to import PST files to Microsoft 365 is available through a Microsoft Enterprise Agreement (EA). Drive shipping isn't available through a Microsoft Products and Services Agreement (MPSA).

What is the pricing for using drive shipping to import PST files to Microsoft 365?

The cost to use drive shipping to import PST files to Microsoft 365 mailboxes is $2 USD per GB of data. For example, if you ship a hard drive that contains 1,000 GB (1 TB) of PST files, the cost is $2,000 USD. You can work with a partner to pay the import fee. For information about finding a partner, see Find your Microsoft partner or reseller.

What kind of hard drives are supported for drive shipping?

Only 2.5-inch solid-state drives (SSDs) or 2.5-inch or 3.5-inch SATA II/III internal hard drives are supported for use with the Office 365 Import service. You can use hard drives up to 10 TB. For import jobs, only the first data volume on the hard drive will be processed. The data volume must be formatted with NTFS. When copying data to a hard drive, you can attach it directly using a 2.5-inch SSD or 2.5-inch or 3.5-inch SATA II/III connector or you can attach it externally using an external 2.5-inch SSD or 2.5-inch or 3.5-inch SATA II/III USB adaptor.

Important

External hard drives that come with a built-in USB adaptor aren't supported by the Office 365 Import service. Additionally, the disk inside the casing of an external hard drive can't be used. Please don't ship external hard drives.

How many hard drives can I ship for a single import job?

You can ship a maximum of 10 hard drives for a single import job.

After I ship my hard drive, how long does it take to get to the Microsoft data center?

That depends on a few things, such as your proximity to the Microsoft data center and what kind of shipping option you used to ship your hard drive (such as, next-day delivery, two-day delivery, or ground-delivery). With most shippers, you can use the tracking number to track the status of your delivery.

After my hard drive arrives at the Microsoft data center, how long does it take to upload my PST files to Azure?

After your hard drive is received at the Microsoft data center, it will take between 7 to 10 business days to upload the PST files to the Azure Storage area for your organization. The PST files will be uploaded to an Azure blob container named ingestiondata.

How long does it take to import a PST file to a mailbox?

After the PST files are uploaded to the Azure Storage area, Microsoft 365 analyzes the data in the PST files (in a safe and secure manner) to identify the age of the items and the different message types included in the PST files. When this analysis is complete, you'll have the option to import all the data in the PST files or set filters to that control what data gets imported. After you start the import job, a PST file is imported to a Microsoft 365 mailbox at a rate of approximately 24 GB per day.* If this rate doesn't meet your needs, you might consider other methods for importing email data to Office 365. For more information, see Ways to migrate multiple email accounts to Office 365.

* This rate is not guaranteed. Server workload and transient performance issues might decrease this rate.

If different PST files are imported to different target mailboxes, the import process occurs in parallel; in other words, each PST/mailbox pair is imported simultaneously. If multiple PST files are imported to the same mailbox, they will be imported sequentially (one at a time), not simultaneously.

After Microsoft uploads my PST files to Azure, how long are they kept in Azure before they're deleted?

All PST files in the Azure Storage location for your organization (in blob container named ingestiondata), are deleted 30 days after the most recent import job was created on the Import PST files page in the compliance portal.

This also means that after PST files are deleted from the Azure Storage area, they're no longer displayed in the list of files for a completed import job in the compliance portal. Although an import job might still be listed on the Import PST files page in the compliance portal, the list of PST files might be empty when you view the details of older import jobs.

What version of the PST file format is supported for importing to Microsoft 365?

There are two versions of the PST file format: ANSI and Unicode. We recommend importing files that use the Unicode PST file format. However, files that use the ANSI PST file format, such as those for languages that use a double-byte character set (DBCS), can also be imported to Microsoft 365. For more information about importing ANSI PST files, see Step 3 in Use drive shipping to import PST files to Office 365.

Additionally, PST files from Outlook 2007 and later versions can be imported to Office 365.

Is there a message size limit when importing PST files?

Yes. If a PST file contains a mailbox item that is larger than 150 MB, the item will be skipped and not imported during the import process. Items larger than 150 MB aren't imported because 150 MB is the message size limit in Exchange Online. For more information, see Message limits in Exchange Online.

How does the PST import process handle duplicate email items?

The PST import process checks for duplicate items and doesn't copy the items from a PST file to the mailbox or archive if a matching item exists in the target folder in the target mailbox or target archive. If you reimport the same PST file and specify a different target folder (using the TargetRootFolder property in the PST import mapping file) than the one you specified in a previous import job, all items in the PST file will be reimported.

Are message properties, such as when the message was sent or received, the list of recipients and other properties, preserved when PST files are imported to a Microsoft 365 mailbox?

Yes. The original message metadata isn't changed during the import process

Is there a limit to the number of levels in a folder hierarchy for a PST file that I want to import to a mailbox?

Yes. You can't import a PST file that has 300 or more levels of nested folders.

Can I use drive shipping to import PST files to an inactive mailbox in Microsoft 365?

Yes, this capability is now available.

Can I use drive shipping to import PST files to an online archive mailbox in an Exchange hybrid deployment?

Yes, this capability is now available.

Can I use drive shipping to import PST files to public folders in Exchange Online?

No, you can't import PST files to public folders.

Can Microsoft wipe my hard drive before they ship it back to me?

No, Microsoft can't wipe hard drives before shipping them back to customers. Hard drives are returned to you in the same state they were in when they were received by Microsoft.

Can Microsoft shred my hard drive instead of shipping it back to me?

No, Microsoft can't destroy your hard drive. Hard drives are returned to you in the same state they were in when they were received by Microsoft.

What courier services are supported for return shipping?

If you're a customer in the United States or Europe, Microsoft uses FedEx to return your hard drive. For all other regions, Microsoft uses DHL.

What are the return shipping costs?

Return shipping costs vary, depending on your proximity to the Microsoft data center that you shipped your hard drive to. Microsoft will bill your FedEx or DHL account to return your hard drive. The cost of return shipping is your responsibility.

Can I use a custom courier shipping service, such as FedEx Custom Shipping, to ship my hard drive to Microsoft?

Yes.

If I have to ship my hard drive to another country, is there anything I need to do?

The hard drive that you ship to Microsoft might have to cross international borders. If so, you're responsible for ensuring that the hard drive and the data it contains are imported and/or exported in accordance with the applicable laws. Before shipping a hard drive, check with your advisors to verify that your drive and data can legally be shipped to the specified Microsoft data center. This will help to ensure that it reaches Microsoft in a timely manner.

Are there any screen resolution requirements when I create an import job for drive shipping?

If the screen resolution on your local computer is set to 1366 x 768, you may have issues creating an import job. If this is the case, we recommend that you change the screen resolution to a different setting and then create a new import job. We're working to fix this issue.