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

Mail Drop attachments don’t behave any differently than attachments sent directly with a message. To recipients using macOS Mail, Mail Drop attachments appear as regular attached files.

Here's how to turn on Mail Drop so that large attachments you send from an Apple Mail account are automatically processed with Mail Drop:

Make sure you have an iCloud account and are signed in to macOS Mail.