How to Send Large Files in Outlook (Attachment Limits and OneDrive Links)

The way to send a large file in Outlook is to upload it to OneDrive and send a link instead of an attachment. Outlook caps attachments at 20 MB for internet email accounts and 10 MB for Exchange accounts by default, and Outlook.com on the web allows 25 MB. When a file is over the cap, Outlook shows an error that says the file is bigger than the server allows and suggests putting it in a shared location and sending a link.

If you are not on Outlook, see how to send large files via email or how to send large files through Gmail.

Outlook attachment limits by account type

Limits below come from Microsoft's own help pages and were last checked on October 16, 2026. Microsoft's pages do not all agree on the Outlook.com figure, so use the lower number if you are not sure. Vendors change limits, so open the linked page if the exact number matters.

Microsoft says the limit includes both the size of the attachment and the size of the email, so a file just under the number can still fail.

How to send a large file in Outlook with OneDrive

Pick the tab that matches the Outlook you use. These steps come from Microsoft's attachment page.

Outlook on the web and Outlook.com

1. Create a new message, or reply to one.
2. Select Attach file, then OneDrive.
3. Choose the file from your OneDrive and select Next. This attaches a link, not a copy of the file.
4. Check who can open it. Microsoft notes that when you attach a OneDrive link, all recipients can view or edit the same file. To restrict editing, open More actions on the attachment and choose Manage access.
5. Send the message.

New Outlook for Windows

1. In a new message, select Attach File on the Message tab.
2. Choose Browse This Computer and pick the file, then open the attachment's down arrow and select Upload to OneDrive. Choose a location. Microsoft says you may upload to OneDrive if the file is too large to share as a traditional attachment.
3. The file now appears as a link. If you picked a file already in OneDrive or SharePoint, Outlook asks whether to send a link or send a copy. Sending a link keeps the size of your email message small.
4. Select the link's arrow to choose permissions, such as Recipients can View.
5. Send the message.

Classic Outlook for Windows

1. In your message, go to the Message tab and select Attach File, then Browse This PC, and choose the file.
2. Open the down arrow on the attachment and choose Upload, then OneDrive, and pick a location.
3. Select the attachment link, then Manage access.
4. Choose who the link works for, and under More settings choose Can edit, Can review, Can view or Can't download.
5. Send the message.

If Outlook spots that your recipients cannot view the file, for example because it sits on a SharePoint site only you can open, it shows a warning. Fix the access, or attach a copy instead if the file is small enough.

Watch your OneDrive space

Uploading to OneDrive uses your cloud storage. Microsoft says a free Microsoft account has 5 GB of free cloud storage, shared across your files and photos in OneDrive, attachments in Outlook.com, and Microsoft 365 apps. A big video or a folder of footage can use that up quickly, so check your free space before you upload.

When OneDrive is not the right fit

OneDrive is the natural choice when your recipients share your Microsoft 365 organization or are happy to sign in or open a link. It is a weaker fit when:

• The file is bigger than the free space left in your OneDrive.
• The recipient is outside your organization and your admin has restricted link sharing.
• You want the link to stop working on its own instead of staying in your OneDrive.

In those cases, upload the file to a transfer service and paste the link into your Outlook message. For video, see how to send large video files via email.

Send a large file from Outlook with Roceet

Roceet sends large files by link. Drop your file below, add an optional title and message, enter your email, and confirm the 8-digit code we send you. You get a share link to paste into your Outlook message. The person you send it to opens the link and downloads the file. They do not need an account.

What you should know before you send:

• Free: up to 2 GB per transfer. You choose when your link expires, up to 2 days. Free has no monthly cap on how many transfers you send, but it does have a 2 GB storage balance, and space is returned when the files are deleted.
• Ultimate: $16.99 per user per month, up to 200 GB per transfer, with links that last up to 30 days. Choose this if your file is larger than 2 GB.
• Controls: you can protect a transfer with a password and limit how many times it can be downloaded. You choose when the link expires, up to your plan's lifetime, and can extend it any time. Expired links can be restored for 2 days on Free and 7 days on Ultimate.

If the file is under your Outlook limit, attach it. If you already use OneDrive and your recipients can open your link, a OneDrive link works well. Use a Roceet link when the file is large, you do not want to spend your OneDrive space, or you want the link to stop working on its own.