I get an email twice a day from Iowa Farmer Today. They publish a free tabloid paper to farmers.
They also offer online content.
This email would be exactly what you want, morning shows the overnight market closings, and the afternoon email shows the closing markets for the day. They throw in a small amount of commentary.
I have not found then to spew out a lot of junk or spam to your email.
The market report is a very, very easy to read chart, green numbers are up, red are down, they list the main grain crops.
They say you can sign up for it here for free:
http://www.iowafarmertoday.com/market_watch/
Other pages that are easy to read, show all the info:
This is the CME, where the grain is traded, directly from the source.
http://www.cmegroup.com/trading/agricultural/
This is a colorful one that shows grains and other markets as well, you can get an idea how the day went just by the red or green tone of the page..... Can click on the other button to get more conventional chart page as well.
http://finviz.com/futures.ashx
Dang, can't fine he one I liked best here on the tablet, have to look on the computer tomorrow. Don't use it now that I get the email one. I really like that email setup....
Paul