The fastest way to attach a file

Open your email in Outlook and look for the paperclip icon in the toolbar at the top of the compose window. Click it once, then select the file you want to attach from your computer. The file will appear as an attachment below the subject line. You can attach multiple files by clicking the paperclip again and selecting another file.

If you don't see a paperclip icon, you may be using Outlook on the web. In that case, look for a plus sign (+) or attachment icon near the bottom of the compose area. Click it and choose "File" or "Browse" to select what you want to send.

The file size matters. Outlook typically limits attachments to 20 MB per file, though your email provider may have different limits. If your file is larger, you'll see an error message when you try to send, and you'll need to use OneDrive or another cloud storage option instead.

Key Takeaways

  • Click the paperclip icon in the compose toolbar to attach a file from your computer.
  • Most Outlook accounts limit individual attachments to 20 MB, so very large files may not send.
  • You can attach multiple files by clicking the paperclip more than once.
  • If you're using Outlook on the web, look for a plus sign or attachment icon instead of a paperclip.
  • Outlook will show you the attachment name below the subject line before you send, so you can verify you chose the right file.

Where the paperclip icon appears in different Outlook versions

In Outlook for Windows (desktop app), the paperclip is in the toolbar at the top of the compose window, usually near the formatting buttons. In Outlook for Mac, it's in the same location but may look slightly different depending on your version.

In Outlook on the web (the version you access through a browser), the attachment button is usually at the bottom of the compose area, below where you type your message. Look for a plus sign, a paperclip, or text that says "Attach" or "Insert".

If you're using Outlook on a phone or tablet, tap the attachment icon (usually a paperclip or plus sign) at the bottom of the compose screen. The exact location varies by device, but it's always near the send button.

Attaching files from OneDrive or SharePoint

If your file is stored in OneDrive or SharePoint instead of your computer, you can attach it directly without downloading it first. In Outlook for Windows, click the paperclip icon and select "Browse This PC" or "Recent Documents" — if your file is in OneDrive, it will appear in the recent files list. In Outlook on the web, click the attachment button and choose "Browse cloud locations" or "OneDrive".

When you attach a file from OneDrive or SharePoint, Outlook gives you the option to share the file as a link instead of sending a copy. This is useful if the file is large or if multiple people need to edit it. You'll see a prompt asking whether to send a copy or a link — choose based on whether the recipient needs their own version or just needs to view it.

What happens after you attach a file

Once you click the paperclip and select a file, the filename appears below the subject line in the compose window. You can see the file size next to the name. If you attached the wrong file, click the X next to the filename to remove it, then click the paperclip again to choose a different one.

Before you send, Outlook checks the file size against your account's limits. If a file is too large, you'll see a warning message. Some email providers also scan attachments for viruses or malware before allowing them through — this can add a few seconds to the sending process, but it's automatic and you don't need to do anything.

The recipient will see the attachment in the email they receive. They can download it to their computer, open it directly in their email client, or (if it's a document) preview it without downloading, depending on the file type and their email provider.

Common reasons attachments don't send

The most common reason is file size. If your attachment is larger than 20 MB, Outlook will block it. Some email providers have smaller limits — Gmail, for example, limits attachments to 25 MB. If you hit this limit, use OneDrive or Google Drive instead and send a link.

Another reason is file type. Some email systems block certain file types for security reasons — executable files (.exe), script files (.bat, .cmd), and some archive formats may be blocked depending on your organization's settings. If you need to send a blocked file type, ask your IT department whether it's allowed, or compress the file into a .zip folder and try again.

If you're using Outlook at work, your organization may have additional restrictions on what you can attach. These are usually set by your IT department to prevent data loss or security breaches. If you can't attach something you need to send, contact your IT support team.

Dragging and dropping files instead of using the paperclip

In Outlook for Windows and Mac, you can drag a file directly from your computer into the compose window instead of clicking the paperclip. Open the file explorer or Finder, find the file you want, and drag it into the message body or the attachment area. The file will attach automatically.

This method works the same way as using the paperclip — the file size limits and restrictions still apply. Dragging is just faster if you already have the file open or visible on your screen. If the drag-and-drop doesn't work, the paperclip method will always work as a backup.

Frequently Asked Questions

Can I attach a folder instead of individual files?

No, Outlook doesn't allow you to attach folders directly. You need to attach individual files. If you want to send multiple files together, you can either attach them one at a time (by clicking the paperclip multiple times) or compress them into a single .zip file first, then attach the .zip file.

What's the difference between attaching a copy and sharing a link?

Attaching a copy sends the file as a separate file in the email — the recipient gets their own version and can edit it without affecting the original. Sharing a link sends a connection to the file in OneDrive or SharePoint — the recipient sees the current version, and if multiple people have edit access, changes are visible to everyone.

Why does my attachment show as a preview instead of a download?

Some file types (like images, PDFs, and Office documents) can be previewed directly in email without downloading. This is a feature of the email client, not a problem. The recipient can still download the file if they want to keep a copy.

Can I attach a file that's currently open in another program?

Yes, you can attach a file even while it's open elsewhere. Outlook will send the version that's saved on your computer, not the version currently in memory. If you've made changes to the file but haven't saved them, those changes won't be included in the attachment.

What if the recipient says they didn't receive my attachment?

First, check that the file actually attached by looking at the filename below the subject line before you hit send. If it was there when you sent it, the problem is usually on the recipient's end — their email provider may have blocked it, or it may have been filtered to spam. Ask them to check their spam folder, or try sending it as a OneDrive link instead.