Google reveals on its Gmail Blog that it has integrated its Google Drive service into Gmail, enabling users to share attachments of up to 10GB, 400x times larger than the previous limit. The file is stored in the cloud, and can be updated after sending.
Have you ever tried to attach a file to an email only to find out it's too large to send? Now with Drive, you can insert files up to 10GB -- 400 times larger than what you can send as a traditional attachment. Also, because you’re sending a file stored in the cloud, all your recipients will have access to the same, most-up-to-date version.

Like a smart assistant, Gmail will also double-check that your recipients all have access to any files you’re sending. This works like Gmail’s forgotten attachment detector: whenever you send a file from Drive that isn’t shared with everyone, you’ll be prompted with the option to change the file’s sharing settings without leaving your email. It’ll even work with Drive links pasted directly into emails.