Email needs a like button

I periodically get large-audience mails at work. For example: "hey, we did a great job at some off-site presentation". I want to give the feedback that I, too, think this is awesome, but don't want to be the next in the reply-all chain of brief answers; I also don't want to spam the sender and have them miss the few potentially interesting responses in there. Facebook (and other social networks) solve this by allowing for a real reply and a like. So clean!
The success of Yammer shows that corporations are buying into a microblogging culture. I've tried this out and it's just awful. Good luck finding a thread from 5 months ago that has relevant information. Good luck even seeing all the things that are interesting to you. Most people try to target posts by tagging those they'd otherwise put on a To: line to ensure notifications, but that only solves half the problem. Newsfeed-based communication is only ok for content that is not critical. That's the whole point: I can pop in anytime and interact with recent content or disappear for a while and not care what flew by when I wasn't looking. And nevermind the separate experience around getting anyone's attention outside of my network or group of friends.

The end result is that newsfeed-based communications aren't much different from everyone sending messages to a group distribution list, and sometimes calling out specific names to avoid email filters shoving those messages out of sight. Yep, because that's where mass messages end up: out of sight. And the sender knows this. And wonders if anyone saw their announcement.

Therefore, email needs a like button.