How to Download All Emails From Outlook 365
In short: To download all emails from Outlook 365, the built-in way is to add the account to classic Outlook, then use File, Open and Export, Import/Export, Export to a file, Outlook Data File. Outlook on the web has no bulk export, so use classic Outlook or a backup tool that saves the whole mailbox with attachments.
Why there is no one-click download
People expect a Download All button in Outlook 365, but there is not one. The reason is how the two versions of Outlook differ. Outlook on the web, where most Microsoft 365 users live, cannot export a mailbox at all. The only built-in way to pull everything is the Import/Export wizard, which exists solely in the classic desktop Outlook. So the job is really about getting your mailbox into a format you control, either a PST through classic Outlook or a full backup through a tool. The routes below cover both, plus the admin option for a whole organization.
Technical Executive and Staff Writer, Corbett Software
“The surprise for most people is that Outlook 365 has no Download All button. The web version cannot export at all. The reliable free route is to add the account to classic Outlook and export a PST. Without that, a backup tool pulls the whole mailbox, attachments included, in one pass.”
Download all emails from Outlook 365 to a PST
This is the standard free method. It needs the classic desktop Outlook with your account added, which you do through the normal Microsoft sign-in.
- In classic Outlook, go to File then Add Account, enter your Microsoft 365 address and complete the Microsoft sign-in.
- Once the mailbox is showing, go to File then Open and Export then Import/Export.
- Choose Export to a file, then Outlook Data File (.pst).
- Select the top of your mailbox and tick Include subfolders to get everything.
- Choose a location, set an optional password and click Finish.
You now have your whole mailbox in one .pst file. A single PST holds up to about 50 GB, so a very large mailbox may need more than one.
Why you cannot export from Outlook on the web
If you only use Outlook 365 in a browser, there is no Import/Export and no bulk download. You can save messages one at a time, which is fine for a few but not for a mailbox:
- Open a message, select the three-dot menu, then Download to save it as a single .eml file.
- Or open the message, choose Print then Save as PDF to keep a read-only copy, covered in our guide on how to save an Outlook email as PDF.
For everything at once from a web-only account, add it to classic Outlook for the PST route above. You can also use the backup tool below, which needs no Outlook at all.
Download all emails from Outlook 365 with a backup tool
If you have no classic Outlook, want more than a PST or simply want it done in one step, a backup tool is the practical route. It signs in with a Microsoft prompt, since Microsoft retired the old password sign-in for apps, then downloads the whole mailbox with attachments.
The Corbett Office 365 Backup Tool connects to your Microsoft 365 or Outlook.com account and saves every folder to your PC as PST, PDF, MBOX or EML, with attachments and the folder structure kept. It previews the mailbox first, filters by date, sender or subject, then a free demo edition runs on every edition of Windows.
- Install and open the tool, then click Open then Email Accounts then Add Account.
- Sign in with your Microsoft 365 credentials and preview the mailbox in the panel.
- Click Export, pick a format such as PST or PDF, apply any date or sender filter, then Save.
For admins: export from Microsoft Purview
If you manage a Microsoft 365 organization and need another user’s mailbox, use the compliance tools rather than their password.
- Sign in to the Microsoft Purview compliance portal as an admin.
- Open Content search and create a search scoped to the mailbox you need.
- Run the search, then choose Export results to download the matching mail as a PST.
This replaces the older Exchange admin center compliance search. For a fuller walkthrough, see our guide on how to export an Office 365 mailbox to PST.
Keep the attachments and save space
A full download is also the safe way to clear space. Once your mail is on your own drive, with attachments intact, you can delete old items from the cloud without losing them. If your goal is a lighter mailbox rather than a full copy, our guide on how to reduce your Outlook mailbox size covers that. And if you are leaving a job, save your mail before your access ends, which our guide on how to keep your work emails when leaving a job walks through.
Frequently asked questions
How do I download all my emails from Outlook 365 at once?
Add the account to classic Outlook, then use File, Open and Export, Import/Export, Export to a file, Outlook Data File to save the whole mailbox as a PST. A backup tool does the same without Outlook installed.
Can I download all my emails from Outlook 365 on the web?
No. Outlook on the web has no bulk export. You can only save one message at a time as EML or PDF. For everything, use classic Outlook or a backup tool.
How do I create a PST file from Outlook Web App?
You cannot do it in the web app directly. Add the same account to classic Outlook and export a PST there. A backup tool can also save a PST from the account without the web app.
Do I need Outlook installed to download all my Office 365 emails?
For the free PST route, yes, classic Outlook is required. A backup tool does not need Outlook, since it signs in to the account itself and saves the mailbox directly.
Does the download include attachments?
A PST export and a backup tool both keep attachments. Saving individual messages as PDF keeps only the body and lists the attachment names, not the files.
How large can a PST file be?
A modern Unicode PST holds up to about 50 GB. A very large mailbox may need more than one PST. A tool that splits the output automatically also helps.
