Most internet service providers (ISPs) and email providers limit the sizes of the files you can upload or send through email. It can be frustrating to see your email returned or blocked because of a large attachment. Why you can’t email large files as attachments Let’s explore other ways to send big files-and help you decide which is best. Have you ever been stopped you in your tracks with an email message like this: “The file you are trying to send exceeds the size limit for email.” Luckily, there are other options for sending large files.