The basic steps differ slightly by email service, but all three let you attach files in under a minute

Attaching a file to an email means uploading a document, photo, or other file from your computer or phone so the recipient can download it. The process is nearly identical across Gmail, Outlook, and Apple Mail: you open a new email, click an attachment button (usually a paperclip icon), select the file from your device, and send. The main differences are where the button sits on your screen and whether you can drag files directly into the message.

File size limits vary by service. Gmail allows up to 25 megabytes per email. Outlook allows 20 megabytes through the web and 25 megabytes through the desktop app. Apple Mail has no hard limit but relies on your email provider's rules. If a file is too large, your email service will warn you before you send.

Key Takeaways

  • Gmail, Outlook, and Apple Mail all use a paperclip icon to attach files, located near the compose area.
  • You can attach files by clicking the paperclip, selecting a file, or dragging a file directly into the message window.
  • Gmail and Outlook limit attachments to 20–25 megabytes; files larger than that will be rejected at send time.
  • If your file is too large, you can compress it, split it into smaller files, or use cloud storage like Google Drive or OneDrive to share a link instead.

How to attach a file in Gmail

Open Gmail and click the "Compose" button to start a new email. Type the recipient's address, subject, and message. Below the message box, you will see a paperclip icon. Click it to open your device's file browser, then navigate to the file you want to attach and click "Open." The file name will appear below the message box once it uploads.

You can also drag a file directly from your computer's file manager into the Gmail message window. Gmail will automatically upload it. If you want to attach multiple files, click the paperclip again or drag additional files into the message. You can attach up to 25 megabytes total per email.

Before you send, Gmail shows you a preview of each attached file with its size. If you need to remove a file, hover over it and click the X that appears. Once you are ready, click "Send."

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

In Outlook on the web, click "New Message" to start composing. After you type your message, look for the paperclip icon in the toolbar above the message box. Click it and select "Upload from this device." Choose your file and click "Open." The file will upload and appear as an attachment below your message.

In Outlook on your desktop (Windows or Mac), open a new email and click the "Attach File" button in the ribbon at the top. Select your file and click "Insert." You can also drag files directly from File Explorer (Windows) or Finder (Mac) into the message body, and Outlook will attach them automatically.

Outlook allows up to 20 megabytes through the web and 25 megabytes through the desktop app. If your file is too large, Outlook will suggest uploading it to OneDrive instead and sharing a link with the recipient.

How to attach a file in Apple Mail

Open Apple Mail and click "File" in the menu bar, then select "New Message." Type your recipient, subject, and message. In the toolbar above the message, click the paperclip icon. Select the file you want to attach and click "Select." The file will appear in the message as an attachment.

You can also drag a file directly from Finder into the message window. Apple Mail will attach it automatically. To attach multiple files, repeat the process or drag several files at once into the message.

Apple Mail does not enforce a strict file size limit itself, but your email provider (Gmail, Outlook, iCloud, or another service) may have one. If your attachment is too large, your email provider will notify you when you try to send.

What to do if your file is too large

If your file exceeds your email service's size limit, you have three options. First, you can compress the file using your device's built-in tools. On Windows, right-click the file, select "Send to," and choose "Compressed (zipped) folder." On Mac, right-click the file and select "Compress." Compression reduces file size but may take a few minutes for large files.

Second, you can split a large file into smaller pieces using file compression software like 7-Zip (Windows) or Archive Utility (Mac). Create separate archives and attach them to multiple emails.

Third, and most practical for very large files, upload the file to cloud storage like Google Drive, OneDrive, or Dropbox. Share the link with the recipient instead of attaching the file. This method also works if the recipient's email service has a smaller size limit than yours.

Common attachment problems and how to fix them

If an attachment does not upload, check your internet connection and try again. Some files may be blocked by your email service for security reasons—executable files (.exe), scripts, and certain other file types cannot be attached. If your file is blocked, compress it into a .zip file, which most email services allow.

If the recipient says they did not receive the attachment, ask them to check their spam or junk folder. Large attachments sometimes trigger spam filters. You can also ask them to check their email storage—if their mailbox is full, new emails with attachments may not arrive. If the problem persists, try uploading the file to cloud storage and sharing a link instead.

On mobile devices, attaching files works the same way but may be slower depending on your internet speed. If you are on a slow connection, wait for the attachment to fully upload before sending the email.

Frequently Asked Questions

Can I attach files from my phone or tablet?

Yes. In Gmail, Outlook, or Apple Mail on your phone, tap the paperclip icon and select a file from your device's photo library, documents folder, or cloud storage. The process is the same as on a computer, though file selection may be slower on mobile networks.

What file types can I attach?

Most file types work: documents (.pdf, .docx, .txt), images (.jpg, .png, .gif), spreadsheets (.xlsx, .csv), videos (.mp4, .mov), and compressed files (.zip). Executable files (.exe, .bat, .scr) and scripts are blocked by most email services for security. If you need to send a blocked file type, compress it into a .zip archive first.

Can I attach files from Google Drive or OneDrive directly?

Yes. In Gmail, you can click the Google Drive icon in the compose window to attach files stored in your Drive account. In Outlook, click "Attach File" and select "Cloud Locations" to browse OneDrive. This method does not count against your email size limit because you are sharing a link, not uploading the file.

What happens if I attach a file and then close the email without sending?

Gmail, Outlook, and Apple Mail all save draft emails automatically. Your attachment will remain in the draft. When you return to the email, the file will still be there. You can continue editing and send whenever you are ready.

Can the recipient edit an attached file?

The recipient can download and edit the file on their own device, but they cannot edit it directly in the email. If you want to collaborate on a document, use Google Docs, Microsoft 365, or another cloud-based tool where multiple people can edit the same file at the same time.