The basic steps for attaching a file

To attach a document to an email, you open a new message, click the attachment button (usually a paperclip icon), browse to the file on your computer, and select it. The file then appears in your message, and you send the email as normal. The exact steps depend on which email service you use — Gmail, Outlook, Yahoo Mail, or your company's email system all have slightly different layouts, but the process is the same.

Most people get stuck at one of two points: they cannot find the attachment button, or they attach the file but forget to actually send the message. Both are easy to fix once you know where to look.

Key Takeaways

  • The attachment button is usually a paperclip icon located near the bottom of the compose window, though Gmail hides it in a menu.
  • You can attach multiple files to one email by clicking the attachment button more than once and selecting a different file each time.
  • File size limits vary by service — Gmail allows up to 25 MB per file, while Outlook allows up to 20 MB, and some company email systems are more restrictive.
  • If your file is too large, you can compress it, split it into smaller pieces, or use a file-sharing service like Google Drive or OneDrive instead.
  • Always check that the file actually appears in your message before you hit send, because the attachment button does not automatically send the email.

How to attach a file in Gmail

Open Gmail and click the "Compose" button to start a new message. Type the recipient's email address, subject line, and message body. At the bottom of the compose window, you will see a paperclip icon — click it to open the file browser. Navigate to the folder where your document is stored, select the file, and click "Open." The file will upload and appear as an attachment in your message.

Gmail also lets you attach files directly from Google Drive, Google Photos, or your computer. If you click the paperclip icon, you will see options for each. For files already in your Google Drive, this is faster than uploading from your computer. Once the file is attached, finish typing your message and click "Send."

How to attach a file in Outlook (web and desktop)

In Outlook on the web, click "New Message" to open the compose window. Type your recipient, subject, and message. Look for a paperclip icon near the bottom of the message area — it may say "Attach" next to it. Click it, then select "Browse this computer" to find your file. Select the document and click "Open." The file will appear in the attachment area above your message body.

In Outlook on your desktop (the program installed on your computer), the process is similar. Open a new message, and look for the "Attach File" button in the toolbar at the top. Click it, navigate to your file, and select it. You can also drag and drop a file directly from your computer into the message window, which is often faster than using the button.

How to attach a file in Yahoo Mail

Click "Compose" to start a new message in Yahoo Mail. Fill in the recipient, subject, and message text. Below the message area, you will see an attachment icon that looks like a paperclip or a plus sign — click it to open the file browser. Find your document, select it, and click "Open." The file will upload and show in the attachment section.

Yahoo Mail also allows you to attach files from Yahoo Cloud Storage if you have files saved there. Once your attachment is in place, click "Send" to deliver the message.

What to do if your file is too large

Most email services limit how large a single file can be. Gmail allows up to 25 MB per attachment, Outlook allows up to 20 MB, and Yahoo Mail allows up to 25 MB. If your file is larger than the limit, you have several options. The simplest is to compress the file — right-click it, select "Compress" or "Send to Compressed Folder" (on Windows) or "Compress" (on Mac), and attach the smaller version instead.

If compressing does not make the file small enough, use a file-sharing service instead. Upload your document to Google Drive, OneDrive, Dropbox, or a similar service, then send your recipient a link to download it from there. This also works well if you need to send multiple large files, because you can share a whole folder instead of attaching each file separately.

Common mistakes and how to avoid them

The most common mistake is clicking the attachment button, selecting a file, and then closing the compose window without sending the message. The file is attached, but the email never leaves your drafts folder. Always check that the file appears in your message before you click "Send," and make sure you actually click "Send" when you are done.

Another frequent problem is attaching the wrong file. Before you send, look at the attachment preview to confirm it is the document you meant to send. If you attached the wrong file, delete it and attach the correct one instead. Some people also forget to mention the attachment in the message itself — a quick line like "I have attached the document you requested" helps the recipient know to look for it.

Finally, do not assume the recipient can open your file format. If you are sending a Word document to someone you do not know well, ask first or convert it to PDF, which opens on almost any device. If you are sending a file from a specialized program (like design software or accounting software), check with the recipient beforehand to make sure they have the right software to open it.

How to attach multiple files at once

You can attach as many files as you want to a single email, as long as the total size stays within your email service's limit. Click the attachment button once, select your first file, and click "Open." Then click the attachment button again and select your second file. Repeat for each file you need to send. All the files will appear in the attachment area of your message.

If you need to send many files, it is often easier to compress them all into a single ZIP file first, then attach that one file instead. This also makes it easier for the recipient to download everything at once. On Windows, select all the files you want to send, right-click, and choose "Send to Compressed Folder." On Mac, select the files, right-click, and choose "Compress."

Frequently Asked Questions

Can I attach a file from my phone or tablet?

Yes, but the process depends on your email app. In Gmail on a phone, open a message, tap the paperclip icon, and select a file from your device's storage or cloud services. In Outlook on a phone, tap the attachment icon and choose a file. Yahoo Mail works the same way. The file size limits are the same as on a computer.

What if the attachment button is not showing up?

Make sure you are in the compose window, not just viewing your inbox. If you are in compose and still do not see the attachment button, try refreshing the page or closing and reopening the email. If you are using a desktop email program like Outlook, check that you are in a new message window and not replying to an existing email — the button location may be different.

How do I know if the file actually attached?

Look at the attachment area of your message before you send. You should see the file name and file size listed. If you do not see it, the attachment did not go through — click the attachment button again and select the file. Some email services show a preview of the file; others just show the name. Either way, if you see the file listed, it is attached.

Can I attach a file that is in a cloud service like Google Drive?

Yes. In Gmail, click the attachment button and select "Google Drive" instead of "Browse this computer." In Outlook, you can attach files from OneDrive the same way. This is useful if the file is too large to upload directly or if you want the recipient to always see the most recent version of the document.

What happens if I attach a file and then edit it before sending?

The email will send with the version of the file that was attached, not any changes you make afterward. If you edit the file after attaching it, you need to delete the attachment and attach the updated version instead. This is why it is a good idea to finish editing your document before you attach it to the email.