Allow .biz address
A website indicates info@theheads.biz as its contact email address. When I try to send an email to info@theheads.biz from my Yahoo account, Yahoo indicates that the address is invalid. I tried the same thing in Gmail and the message went out just fine, and I received a reply from the person to whom I emailed.
I'm not sure which versions of Yahoo Mail have this bug, but I was using the webmail version. If Yahoo personnel read this soon, they will be able to see the message I tried to send, because it's the most recent one in my Drafts folder.

Hi there,
Could you please message us on Twitter at @YahooCare or on Facebook at Yahoo Customer Care? We'd like to look more into the issue you're experiencing. In case you do not have a social media account, we are also available at: help.yahoo.com
Looking forward to your reply!
Thank you,
Yahoo Mail team