Most email providers cap attachments at 25MB (Gmail, Outlook.com) or 20-25MB (most others) — enough for a handful of photos but nowhere near enough for a video file, a folder of raw camera images, or a large PDF portfolio. When an attachment exceeds the limit, the email either bounces back undelivered or silently fails depending on the provider, which is a bad way to find out mid-transfer. There are better ways to move large files that are also, done correctly, more secure than an attachment ever was.
Why the Attachment Limit Exists in the First Place
Email wasn't designed to move large binary data efficiently. Every attachment gets encoded into a text format called Base64 for transmission, which inflates the actual file size by roughly 33% before it even leaves your outbox. Mail servers also have to store a full copy of every attachment for every recipient's mailbox, which doesn't scale — a 500MB video sent to ten people means 5GB of server storage just for that one message. Cloud transfer tools solve this by storing one copy and sending recipients a link instead.
Cloud Storage Links: The Simplest Fix
If you already use Google Drive, OneDrive, or iCloud, the fastest fix is to upload the file there and share a link instead of attaching the file directly. This also lets you set the link to expire, require the recipient to sign in, or restrict it to view-only so they can't accidentally overwrite the file. The tradeoff is that the file sits on that cloud account indefinitely unless you remember to delete it — worth a calendar reminder for anything sensitive.
Dedicated Large-File Transfer Services
For one-off transfers where you don't want the file living permanently in your cloud storage, dedicated transfer services are built for exactly this: upload once, generate a link, the link expires automatically after a set number of days or downloads. Look for services that offer:
- Password protection on the link — so the file isn't accessible to anyone who merely guesses or intercepts the URL.
- End-to-end encryption — meaning the service itself can't read the file contents, only the encrypted blob. Not all "secure" transfer tools actually offer this; check the provider's own documentation rather than assuming from marketing language.
- Automatic expiration — a file that deletes itself after 7 days or after being downloaded once is safer by default than one sitting on a server indefinitely with a guessable link.
Compressing Before You Send
Sometimes the simplest fix is shrinking the file rather than finding a new way to send it. Zipping a folder of documents, or using a tool to compress a video or a batch of images, can bring a file under the attachment limit entirely. Our guide on compressing and extracting files with 7-Zip covers this for general files, and if the bulk of the size is coming from photos specifically, compressing images without losing quality can often cut a batch down by half or more before you even reach for a transfer service.
Encrypting a File Yourself Before Upload
For genuinely sensitive material — tax documents, medical records, legal files — the most reliable approach is to encrypt the file yourself before it ever touches a third-party server, rather than trusting that the transfer service's built-in encryption is configured the way you assume. Compressing a folder into a password-protected 7-Zip or WinRAR archive with AES-256 encryption means that even if the transfer link is somehow intercepted or the service is compromised, the archive itself is unreadable without the password you set — which you can then relay to the recipient over a separate channel like a phone call.
What to Avoid
Skip file-sharing links posted in public forums, Discord servers, or anywhere the URL might get indexed or forwarded beyond the intended recipient — many transfer services generate URLs that are only "secure" in the sense that they're hard to guess, not because they're actually access-controlled. If the service doesn't offer a password option, treat the link as effectively public once it's sent, and don't use it for anything you wouldn't be comfortable being briefly exposed. For guidance on data handling and privacy expectations when using third-party cloud services, the U.S. Federal Trade Commission publishes consumer-facing advice at consumer.ftc.gov.