How to turn on Yosemite's Mail Drop feature for non-iCloud email accounts

[iMore.com]

One of the many new features introduced in OS X Yosemite is Mail Drop, which enables you to attach files up to 5 GB regardless of your email service provider's limitations. Did you know it works with non-iCloud email, too? Here's what you need to do to get it working.

Full story from the iMore Blog...

 

[HankAZ]

There is no such option in my Yosemite Mail app. The option only appears on the Advanced Settings tab for iCloud email address.