Article

Microsoft 365 export: mail, SharePoint, Teams

By TrustPast

Updated October 22, 2026

A company of 30 or more on Microsoft 365 keeps its record in four places: Outlook mailboxes, SharePoint sites, OneDrive folders and Teams. A buyer pays to license records like these to train AI models. You don’t export anything to apply. You count what you have, and an export comes later, if at all, after an agreement says what it covers. This guide settles what to count, where Microsoft shows the numbers, and how Microsoft’s two export routes work, in Microsoft’s own words.

Checked on 22 October 2026 against Microsoft’s help pages for classic Outlook and for Microsoft Purview eDiscovery with Microsoft 365 E3 or E5 licences, linked at each step. Menus change. If a step here differs from Microsoft’s page, Microsoft’s page wins.

You don’t export to apply

micro1 is the buyer on this page. micro1’s published steps start with the company, not with files. First “Get started”. Then “Evaluation”, where “Our team reviews your submission”. Then “Discovery”, where, if there is a potential fit, “we’ll request additional information”. Then “Partnership”. Nothing in those steps asks for an export. Its estimator asks “How many employees does your company have?” and “How many years of data do you have?”, with the note “Typically the number of years you’ve been in business”.

Files come later, and only inside an agreed scope. micro1 publishes this, word for word: “Before any participation, together we define:”

“Approved data scope and clear boundaries”
“Security and confidentiality standards”
“Anonymization and redaction requirements”
“Internal approval processes and permissions”

Then: “If approved, we’ll finalize the agreement and data requirements and begin the partnership.”

micro1 does not publish how records are delivered; that is agreed in its scope step. So this guide does not tell you to send a file anywhere. It shows what Microsoft’s tools produce, so the scope you agree to is one you can actually run.

Our advice: count first. Export after an agreement, and only what it names. An eDiscovery search across “All people and groups” is every mailbox in the company. Nobody needs that copy to fill in an application.

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How much you have, and where Microsoft shows it

The numbers that matter are people, mailboxes and years. Microsoft shows the first two in its usage reports.

The one for mail is the Exchange Mailbox usage report. Microsoft’s path: go to the Microsoft 365 admin center; select Reports (or Show all, then Reports); select Usage; under Reports, select Exchange; select the Email activity tab; select View More; then, from the Email activity list, select Exchange > Mailbox usage. (Microsoft’s mailbox usage page)

Its table lists, for each mailbox, “Item count”, described as “The total number of items in the mailbox”, “Storage used (MB)”, “Create date” and “Has Archive”. A switch at the top shows shared mailboxes too. “To export the report data into an Excel .csv file, select Export.”

Microsoft lists other usage reports in the same place, among them OneDrive usage, SharePoint site usage, SharePoint storage and Microsoft Teams team activity. Those give the file side and the Teams side in the same way. (Microsoft’s usage reports overview)

Two things to know before you open them. First, the roles. Microsoft lists who can view usage reports, among them Global Administrator, Exchange Administrator, SharePoint Administrator, Reports Reader and Teams Administrator. Second, the names. “By default, all reports hide user information such as usernames, display names, groups, and sites.” A Global Administrator can change that under Settings > Org Settings > Services > Reports. For a count, you don’t need the names at all.

The years are yours to find. Our own method:

In the mailbox usage export, sort by “Create date”. The oldest mailbox is where the record starts, or close to it.
Open that mailbox and sort by date. Note the first message.
Open the oldest SharePoint site. Note the year of the earliest document still there.
Note any migration. A company that moved to Microsoft 365 in 2018 may hold the earlier years in old PST files on someone’s computer.
List the Teams teams and channels that carry the work, and the year each started.

That gives you five lines: people, mailboxes, sites, years of mail, years of files. That is what we would bring to the first call; micro1’s estimator asks for two of them, employees and years.

Who can export, and what the plan allows

Microsoft has two routes, with different gatekeepers.

Outlook’s export is for one account, run by the person signed in to classic Outlook. Microsoft says: “Only information for one account can be exported at a time.” Microsoft’s PST page names no admin role and no plan limit for it. It has three limits that matter for a company record. “If you’re using Cached Exchange Mode, Outlook will only export the items in your current cache.” “By default, your cache contains items from the past 12 months.” And Microsoft warns: “Make sure you don’t export your .pst file to a OneDrive location.” (Microsoft’s PST page)

New Outlook is different. Microsoft says “Calendar and contacts items saved in .pst files is not available in new Outlook at this time.” The export steps below are for classic Outlook.

eDiscovery is the company route. It runs in the Microsoft Purview portal. Step one is to sign in “with the credentials for a user account assigned eDiscovery permissions.” On licences, Microsoft says: “To export content in eDiscovery, assign the eDiscovery user a Microsoft 365 Enterprise E3 or E5 license. When exporting SharePoint content, the account must also have a Microsoft SharePoint E3 license; otherwise, SharePoint items might not export as expected.” (Microsoft’s eDiscovery export page) The export page does not name the exact role group behind “eDiscovery permissions”; Microsoft does not publish that on this page.

Microsoft also lists what eDiscovery will not export. Files “restricted by DLP action”. Content “stored in SharePoint sites that are in a Locked state with NoAccess”. And files “restricted by SharePoint access controls”, unless the collecting user has direct access, for example as a site admin, site owner, or the owner or last modifier of the document.

The steps, in Microsoft’s words

These are Microsoft’s steps, quoted or kept to Microsoft’s menu names. Each ends with its page. Run them after an agreement, not before.

One person’s mailbox: a PST from classic Outlook

“At the top of the ribbon in classic Outlook, choose File.” (source)
“Choose Open & Export > Import/Export.” (source)
“Choose Export to a file > Next.” (source)
“Click Outlook Data File (.pst) > Next.” (source)
Select the email account to export. “Make sure that the Include subfolders check box is selected.” (source)
“Click Browse to select where to save the Outlook Data File (.pst).” Enter a file name and choose OK. (source)
If you are exporting to an existing file, under Options, specify what to do with items that already exist in it. (source)
“Choose Finish.” (source)

Microsoft says Outlook “begins the export immediately” unless a new or password-protected file is created. It also says: “When Outlook exports email, contacts, and calendar info to a .pst, it makes a copy of the information.” And: “Nothing leaves Outlook.” The mailbox stays as it was.

Many mailboxes, sites and Teams: an eDiscovery export

Microsoft’s procedure has 17 steps. Here they are, condensed to 15, with the options that change what the file holds.

Go to the Microsoft Purview portal and sign in “with the credentials for a user account assigned eDiscovery permissions.” (source)
“Select the eDiscovery solution card, and then select Cases.” (source)
“Select a case, select the Searches tab, and then select a search query to export.” (source)
“In the search query, select Export.” (source)
On the Export pane, enter an export name, which is required, and an optional description. (source)
Under Tenant-wide source configuration, choose whether “All people and groups” should include unlicensed and on-premises users, guest users, shared Teams channels and departed users. (source)
Under Select items to include in your export, choose indexed items that match the query, partially indexed items, or both. (source)
Under OneDrive and SharePoint items, choose the document versions: “Latest version only”, “Recent 10 versions”, “Recent 100 versions” or “All versions”. (source)
Under Messages and related items from mailboxes and Exchange Online, choose whether to “Organize conversation into HTML transcript”, “Include Teams and Viva Engage conversations”, and collect cloud attachments from links in messages. (source)
Under Export type, choose “Export items report only” or “Export items with items report”. (source)
Under Export format, choose “Create PSTs for messages” or “Create .msg files for messages”. (source)
Under Package size settings, set the PST size to 1 GB, 2 GB, 5 GB (the default) or 10 GB, and the .zip size to 2 GB, 10 GB (the default), 20 GB or 40 GB. (source)
Choose the package options: separate folders or PSTs per location, the folder and path of the source, condensed paths, friendly names. (source)
“Select Export.” When the confirmation dialog appears, select OK. (source)
Watch progress and download the packages from Process manager. Microsoft says: “You can download search export packages for 14 days from the export creation time.” (source)

Three of Microsoft’s rules shape the job. “If an export runs for more than seven days without completing, it automatically cancels.” Search export packages “expire 14 days after you create the export”, after which they “can’t be recovered.” And “Export package download links are for individual use only. Don’t share them.”

Step 10 is the one to use first. “Export items report only” produces a summary and the item report, with no message content. That is a count, made by Microsoft, of exactly what a scope would cover. Our advice is to run that before anything else, if an agreement ever asks for an export.

What the file contains

From Outlook, one PST file per account. Microsoft says “When Outlook exports emails, it includes any attachments to the emails.” It also says Outlook “does not export meta-data such as folder properties (views, permissions, and AutoArchive settings)”, “message rules, and blocked senders lists.”

From eDiscovery, zip packages. Inside them: mailbox items as PST or .msg files; copies of the native documents from SharePoint and OneDrive, in the versions you chose; Teams and Viva Engage messages if you chose them; and an item report, items.csv, that records the source location and metadata of each item. With the separate-locations option, “The system exports each mailbox’s content into a separate PST file named after the mailbox.” Without it, all mailbox content merges into one PST, split when it passes the size you set. Microsoft adds that items from a primary mailbox and its archives merge into a single PST either way.

Two details, as our own reading of Microsoft’s page. The Teams option does not export every chat in the company. It adds “messages posted within a 12-hour window before and after each responsive item.” What the search matches decides what comes out. If your chat lives in Slack, see the Slack guide. And cloud attachments, the files linked from mail, are exported as part of the message. Microsoft says “Including cloud attachments increases the size and quantity of your exported results.”

Microsoft also says the export keeps the original timestamps: “Microsoft Purview eDiscovery doesn’t modify or rewrite timestamps.” Local zip tools may change file dates, so the items.csv is the record of when things happened.

The personal data in it

A company mailbox holds the work and the people around it. Customer names and addresses. Staff matters. Personal mail at a work address. SharePoint holds HR folders beside project folders. Teams holds the side conversations beside the job threads.

micro1 publishes how it treats that. “Personally identifiable information (PII) is removed when relevant, access is restricted to a limited number of authorized team members, and customer data is processed through isolated pipelines that prevent it from being commingled with other engagements.” It adds that “certain datasets may undergo synthetic rewrites that preserve workflow structure while reducing direct ties to original records.”

It also publishes the checks the company keeps. “Data is retained only for agreed periods, companies have the opportunity to review representative samples before use, and deletion requests are honored according to the terms of the engagement.” On ownership: “Companies retain ownership of their underlying data.”

What that means in practice, as our own advice:

Agree the redaction rules before any export. micro1 puts “Anonymization and redaction requirements” in the list it defines “Before any participation”.
Use the sample review. Ask to see representative samples from your own mailboxes before prepared data is used.
Write the scope as a list: mailboxes, sites, channels, dates. An eDiscovery search can be built from exactly that list.
Don’t clean the mailboxes yourself. Deleting mail changes the record and may breach your retention rules. The redaction step exists for this.

What is never included

micro1 says every partnership has “clear controls over what is shared, how it is handled, and what is never included.” micro1 settles the list with each company in its scope step. It does not publish one fixed list for Microsoft 365 data.

Here is what we tell owners to keep out, as our own advice, not micro1’s:

the HR and payroll mailboxes, and SharePoint sites with salaries, reviews or medical notes;
attorney-client mail and anything your lawyer marked privileged;
payment-card numbers, bank details and Social Security numbers, wherever they turn up;
health information about staff or customers;
anything a client owns under contract, such as files a client supplied that the contract says stay theirs;
personal folders, private Teams chats that are not about the work, and anything from minors.

Three Microsoft settings sit beside that list. The tenant-wide options in step 6 can pull in guests and departed users; leave them off unless the scope names them. The cloud-attachment option in step 9 can pull a file from a site you meant to keep out. And “All versions” in step 8 exports every draft of a document, including a version that held something later removed.

Check the export

If an agreement asks for an export, check it before it goes anywhere. Five checks, as our own advice:

The scope. Compare the mailboxes and sites in items.csv with the list in the agreement. Nothing extra.
The dates. Sort items.csv by date. The oldest and newest items should match the agreed range.
The counts. Compare the item totals with the “Item count” column of the mailbox usage report for the same mailboxes.
The gaps. Microsoft says DLP-restricted files, locked sites and restricted files can appear in search results but are excluded from the export. Note any you find.
The expiry. Download within 14 days, and keep the packages somewhere access-controlled. The links are for one person.

Other office systems

Many companies run more than one system. A company that moved from Google Workspace still has years of mail there. The Google Workspace export guide does the same job for Gmail, Drive and Chat. The Zendesk export guide covers a support desk, where the customer side of the work sits.

The records themselves are described elsewhere on our site. The email archives page goes through what a company inbox shows about how the work was done. The chat archives page does the same for Slack and Teams. Both are written for trade companies; the shape of the record is the same in an office.

Where we fit

We, TrustPast, explain the process and give you a range with our estimate. The estimate is ours, not an offer. You apply to micro1 yourself, through the button on this page, with counts, not files. micro1 pays us a referral fee. You pay us nothing. We never see your mail, your sites or your exports. Why buyers want records like these at all, and what they leave out, is on what data buyers actually want from a trade business.

What a company of 30 or more holds, and why that headcount is micro1’s published line, is on the page for companies with 30 or more staff. What happens after the application is on what happens after you apply. How the records are protected is on how it’s safe.

Worth two minutes to see your range? Run the mailbox usage report first.

TrustPast

Questions and answers

Do we have to export our mailboxes to apply to micro1?

No. micro1’s estimator asks how many employees and how many years of data; we would bring a few more counts to the first call: mailboxes, sites, years of mail. micro1 says the approved data scope is defined together “Before any participation”. micro1 does not publish how records are delivered; that is agreed in its scope step. Run an export only after an agreement names it.

Which export should a company use, Outlook or eDiscovery?

Outlook exports one account at a time, to a PST file on one computer. eDiscovery exports many mailboxes, SharePoint and OneDrive sites, and Teams messages from one search, with a report of every item. For a company record, eDiscovery fits a written scope; Outlook is for one person’s mailbox.

What licence does an eDiscovery export need?

Microsoft says to assign the eDiscovery user a Microsoft 365 Enterprise E3 or E5 licence, and, for SharePoint content, a SharePoint E3 licence as well. The user also needs eDiscovery permissions.

Does a PST from Outlook hold the whole mailbox?

Not always. Microsoft says that with Cached Exchange Mode, Outlook only exports the items in the current cache, which by default holds the past 12 months. Change the setting first, or use eDiscovery.

How long do we have to download an eDiscovery export?

14 days. Microsoft says search export packages expire 14 days after you create the export and are then deleted and can’t be recovered. An export that runs for more than seven days without finishing is cancelled.

Are Teams chats part of the export?

They can be. In the eDiscovery export pane, Microsoft offers “Include Teams and Viva Engage conversations”, which adds messages posted within a 12-hour window before and after each responsive item. Whether Teams is in scope is something to settle with micro1 before any export.

Should we delete personal mail first?

Our advice: don’t delete anything to apply. micro1 says the anonymization and redaction requirements and the internal approvals are defined before participation. Name the mailboxes and sites to leave out on that call, and keep them out of the scope in writing.