How to Send Large File Attachments (Up to 5 GB) in Apple Mail

With an iCloud account and macOS Mail, you can use Mail Drop to automatically upload files that are too large for an email to the iCloud servers. There, they are stored in encrypted form and available to be downloaded by any recipient with the link for up to 30 days.

Enable Mail Drop for an Email Account in OS X Mail

Mail Drop attachments operate no differently than attachments sent directly with a message. For recipients using macOS Mail, Mail Drop attachments present as regularly attached files.

Here's how to turn on Mail Drop so large attachments sent from an Apple Mail account are automatically processed using Mail Drop:

1. Make sure you have an iCloud account and that you are signed in to it with macOS Mail.

2. Select Mail > Preferences from the menu bar in Mail.

3. Select the Accounts tab.

4. From the accounts list, select the account for which you want to enable Mail Drop.

5. Check the box next to Send large attachments with Mail Drop.

6. Close the Preferences window.

Send Large File Attachments (Up to 5 GB) in Apple Mail

Here's how to send files up to 5 GB in size via email from macOS Mail:

1. Make sure Mail Drop is enabled for the account you are using.

2. Use one of the following methods to add files or folders to a message you are composing in macOS Mail:

   • Position the text cursor where you want the attachment to appear. Select the Paperclip icon (📎) in the message's toolbar. Highlight the desired document or folder, then select Choose File.
   • Make sure the cursor is where you want to insert the file or files. Select File > Attach Files… from the menu or press Command+Shift+A. Select the desired files and folders, then select Choose File.
   • Drag and drop the desired document or folder onto the message body where you want the attachment to appear.

For attachments exceeding a certain size (it depends on your email provider), Mail automatically uploads the file in the background to an iCloud web server, where recipients can download the file by following a link in the message. The files are available for 30 days.

Is Bigger Better for Attachments?

As anyone who has ever tried to attach a large file to an email has discovered, bigger is not always better. Big files cause delays, waiting, errors, repetition, and undelivered messages, not to mention frustration.

You can go hunting for services, plug-ins, and apps to work around the problem, including file transfer services like Dropbox and WeTransfer, or you can use Apple's built-in solution.