To attach a file to a message you're composing, follow these steps:
- Click Attach a file under the subject field.
- Browse through your files and click the name of the file you'd like to attach. You can also choose multiple files at this time by using the "Shift" or "Cmd/Ctrl" keys.
- Click Open.
You should see a progress bar that tracks the status of your attached file.
If you'd like to remove a file you've attached to a message, simply uncheck the box next to the file before sending.
To attach another file, click Attach another file.
If your email contains reference to an attachment, but you forget to add one, Gmail can remind you. The reminder will appear as a popup when you click send, if you have not attached files to the message but Gmail thinks you intended to.
For example, if you compose an email that says, "Hi Mike, I'm attaching the latest reports" and then click Send before attaching any files, Gmail will remind you with this popup:
This is automatic and does not require you to enable a lab to access this feature.