Send large files by email on a Mac

Email providers cap attachments — Gmail, for example, at around 25 MB — so for very large files the honest answer is a link. macOS Mail's built-in Mail Drop uploads files up to about 5 GB to iCloud and sends a download link. For anything within the provider limit, AutoMailSender attaches and sends the file directly over SMTP. Free for your first 25 emails, then a one-time €9.99.

First, the native macOS way (and when it wins)

Every email provider limits attachment size — Gmail is commonly around 25 MB, and others are in the same ballpark. If your file is bigger than that, a direct attachment simply won't go through, and that's true no matter which app you use.

macOS Mail solves this with Mail Drop: when an attachment is too large, Mail uploads it to iCloud (up to roughly 5 GB) and sends the recipient a download link instead of the file. It's free, built in, and for multi-hundred-megabyte or multi-gigabyte files it's the right tool. Dedicated link services like WeTransfer are also a good fit for very large transfers. Be honest with yourself about size before picking a method.

Send it with AutoMailSender

If your file fits within the provider's limit and you'd rather it arrive as a real attachment — not a link the recipient has to click and download — AutoMailSender sends it straight from your Mac:

1. Connect your email account once — Gmail, Outlook / Office 365, iCloud, Yahoo, or any custom SMTP server. Credentials stay in the macOS Keychain.
2. Add the recipient so you never retype the address.
3. Drop the file to send it — AutoMailSender attaches it directly over SMTP within your provider's size limit, no compose window.
4. Blocked file types are packaged automatically — if the provider rejects a file type (like an executable), AutoMailSender wraps it in a password-protected AES-256 ZIP so it arrives intact.

For a genuinely huge file — several gigabytes — a link-based service is the better choice, and Mail Drop already does that natively. AutoMailSender is for getting real attachments out fast, again and again, without a compose window.