It seems that Yahoo is deferring or blocking a portion of the email we send users with a yahoo.com email address.

I am jumping through all the hoops* that may help the problem. In the meantime, if you want, you could send a message to the Yahoo email people and request that they quit being mean to Tanga and let our email through.

• http://en.wikipedia.org/wiki/DomainKeys and http://www.dkim.org