I think you only have three choices: (1) burn it to CD and mail it; (2) email it; or (3) upload it to a server on the web where others can download it.
For the most part, burning it to CD and mailing it is a method that has been used by many for years. However, it takes time to burn, mail and deliver.
If you choose to email it, you have to keep in mind that the recipient's email server may be set up to reject attachments over a certain size. Most companies (including free email services) place caps on the size of email messages to avoid stress on the email system. Emailing also presents security issues, since messages are typically sent unencrypted over the internet which means a hacker could intercept them.
Traditionally, companies have used FTP (file transfer protocol) folders on web servers they have access to. Essentially, it's a shared folder that allows anyone with a password to access the folder. This is not a good option if you intend to use the same FTP site for all of your clients.
There is a free service out there (www.drop.io
) which allows you to anonymously create an FTP type site and set a password to restrict access. It's very easy to navigate, and you can set up as many of these sites as you have clients. Just remember to delete the information after you don't need it anymore, since you are restricted to 100 MB per site.