When you send a big attachment via email a lot can go wrong. First, your own email provider can reject the attachment for being too big. Second, even if that doesn’t happen, the recipient’s email provider can reject the attachment for being too big. And, even if it neither of those things happens, sending big attachments impacts your own account and the recipient’s account in a bad way– send too many big messages and you’ll get a notification about your Sent mail being over quota. Your recipient may get one too, about his Inbox. Sending big attachments via email is a bad way to go.
If the person you’re sending to has Messages, you can use Messages to send your big attachments and never have a problem, because it’s person-to-person, about as direct a transfer as you can get without getting all techie about it. Just drag the item you want to send into the area where you ordinarily type messages, and press Return. If it’s a picture the other person just sees it show up, and he can drag it out of Messages and onto his Desktop. If it’s something else, like a folder full of stuff, the recipient will see a little down-arrow and will have to click it to download. The little down-arrow will change to a magnifying glass so the recipient can find the download when it’s done. Really easy. And no restrictions on size. Try it next time.