The basic way to attach a file

To attach a document in Outlook, open a new email or reply to one you have received. Look for the paperclip icon in the toolbar at the top of the compose window — it is usually near the formatting buttons. Click it once, and a file browser window opens on your computer.

Navigate to the folder where your document lives, select the file you want, and click Insert or Open (the button name depends on your version). The file name will then appear in the Attachments area below the subject line. You can attach multiple files by repeating this step.

Once you have attached what you need, finish writing your email and click Send. The attachment travels with the message to the recipient's inbox.

Key Takeaways

  • The paperclip icon in the compose toolbar is the standard way to attach files in Outlook on any device.
  • You can attach multiple documents to a single email by clicking the paperclip icon more than once.
  • Large files may take longer to send, and some email systems reject attachments over a certain size — usually 20 to 25 megabytes.
  • If you cannot see the paperclip icon, you may be in a simplified compose view; look for a menu button or switch to full compose mode.

Where the paperclip icon is in different Outlook versions

In Outlook on the web (the version you use in a browser), the paperclip icon sits in the toolbar directly above the message body. It is usually one of the first icons you see after the formatting buttons.

In Outlook desktop (the program you install on Windows or Mac), the paperclip is in the ribbon at the top of the compose window, grouped with other message tools. On Mac, it may appear in a different location depending on your version — check the Message menu if you cannot spot it in the toolbar.

In Outlook mobile (the app on your phone), the attachment icon is usually a paperclip or a plus sign. Tap it to open your phone's file browser and select a document from your device storage.

What happens when a file is too large

Most email systems have a size limit for attachments. If your file is larger than the limit — commonly 20 to 25 megabytes — Outlook will either prevent you from sending the email or the recipient's email system will reject it. You will usually see an error message before you send, telling you the attachment is too large.

If you hit this limit, you have two options. The first is to compress the file: right-click it on your computer, select Compress or Send to > Compressed folder (Windows) or Compress (Mac), and attach the smaller version. The second is to use a file-sharing service like OneDrive, Google Drive, or Dropbox — upload the file there, copy the sharing link, and paste it into your email instead of attaching the file itself.

Removing or replacing an attachment

If you attached the wrong file or want to remove an attachment before sending, look for the attachment name in the Attachments section below the subject line. Hover over it or right-click it, and an X or Remove button will appear. Click it to delete the attachment from your email.

To replace a file, straightforward remove the old one and attach the new one using the paperclip icon again. There is no need to start the email over.

Attaching files from OneDrive or SharePoint

If your document is stored in OneDrive or SharePoint (Microsoft's cloud storage services), Outlook gives you a faster option than downloading and re-uploading. In the compose window, look for an icon that says Insert > Files or Browse Cloud Locations — the exact wording varies by version.

Click it, and you can browse your OneDrive or SharePoint folders directly without leaving Outlook. Select the file, and Outlook will insert a link to it rather than copying the whole file into the email. This keeps your message size small and ensures the recipient always sees the latest version if you update the document later.

Why your attachment might not go through

Sometimes an attachment fails to send even though you attached it correctly. The most common reasons are file size (covered above), a network interruption while Outlook was sending, or security software blocking the file type. Certain file types — like .exe files or scripts — are blocked by many email systems for safety reasons.

If you get an error message, read it carefully — it usually tells you what went wrong. If the file type is blocked, ask the recipient if they can receive it in a different format, or use a file-sharing link instead. If it is a network issue, wait a moment and try sending again.

Frequently Asked Questions

Can I attach a file directly from my email without downloading it first?

No — you cannot attach an email you received to a new message by using the paperclip icon. Instead, use Forward to send the original email and its attachments to someone else, or right-click the attachment in the original email and select Save As to read it, then attach it to your new message.

What is the difference between attaching a file and inserting a link?

An attachment copies the file into the email itself, so the recipient gets their own copy. A link (from OneDrive, Google Drive, or similar) points to a file stored online — the recipient clicks the link to view or read it. Links keep email size small but require the recipient to have permission to access the cloud service.

Why does my attachment show as a preview instead of a file name?

Outlook sometimes displays images, PDFs, and other files as previews in the message body rather than as separate attachments. This is normal and does not change how the recipient receives the file — they will still get the full document. If you prefer to see it as a traditional attachment, you can usually right-click and choose read or Save.

Can I attach a folder instead of individual files?

No — email systems do not accept folders as attachments. You must attach individual files. If you need to send multiple files, attach them one at a time using the paperclip icon, or compress the folder into a single .zip file and attach that instead.

What if the recipient says they did not receive my attachment?

Ask them to check their spam or junk folder — attachments sometimes trigger spam filters. If it is not there, the file may have been blocked by their email system or your network. Try sending it again, or use a file-sharing link instead. If the file is very large, compression or cloud storage is usually more reliable.