Yahoo Mail - Abuse Prevention vs. Usability

Yahoo Mail is a free email service which I like primarily for its 1 TB of storage capacity. I'm generally satisfied with Yahoo Mail--its ads are not too obtrusive, there are keyboard shortcuts to perform common actions like archiving emails, and its spam filter does a pretty good job (sometimes "a little too well" but that's another story). However, sometimes Yahoo Mail borders on annoying, and here is an example. Sometimes I come across an interesting story or video that I don't have time to read/watch at the moment, so I send myself the URL for future reference. When I use Yahoo Mail to send the URL, I get this message:

This occurs when the body contains only a URL, regardless of whether the subject line is populated. It doesn't occur every time I send just a URL, and I don't know how to predict when it will occur. I  do appreciate Yahoo's efforts to prevent spam, but when preventive efforts impede regular non-abusive users from doing what they want to do, that's when usability has been compromised.

I realize that there are many examples of when the masses are inconvenienced to screen for a small minority of offenders. Airport security checkpoints and border inspections come to mind. But is the presence of spam email enough justification to disallow sending of URLs via email where there are a multitude of ways that email can be used to send spam and commit more serious forms of abuse? How about if emails were intercepted only if the URLs had a poor Web of Trust reputation or if the URL had been associated with phishing attempts for the purpose of identity theft?

With Yahoo Mail's current implementation of abuse prevention, a spammer simply needs to add some text in addition to the URL in the body of the email, and presto--Yahoo's preventive measures are bypassed. Surely there must be a better way to fight spam?