If you have to email a large file, up to 50 MB for free, YouSendIt.com does a great job. I’ve used it, with great success, to email large files that my corporate email account would not allow. The file gets securely stored on the YouSendIt servers and a link is sent to the recipient. The recipient clicks on the link and they start downloading the file. If your file is over the 50 MB size, try zipping it up first.