Yahoo has announced their latest developer platform, the Yahoo Mail web service. John Kremer, vice president for Yahoo Mail, told WebProNews he hopes to see developers leverage Yahoo Mail’s 250 million users to build innovative and interesting applications like the Flickr postcard created during their Hack Day event last September.

Yahoo Developer Network leader Chad Dickerson also disclosed an extra incentive for approved developers. Applications that drive new members to the premium service, Yahoo Mail Plus, will earn the developer ten dollars for each referral who joins. Developers building applications for Yahoo Mail Plus will have access to the full set of features available through the API.

Has anyone ever asked you for advice and then told you that your idea was stupid? That’s how Yahoo Suggestions user David Dalka feels after Yahoo not only rejected his suggestion about improving Yahoo mail, but deleted it entirely.

Yahoo recently unveiled its new Digg-like Suggestions platform that, at least in theory, allows users to propose ideas and invites the community to vote on the ideas they’d like to see Yahoo implement.

Dalka learned that the first rule of Yahoo Mail is you don’t talk about Yahoo Mail — at least not negatively. After Dalka brought up issues with Yahoo Mail’s spam filters, the Yahoo Suggestions community chimed in with support. Apparently, Yahoo thought more aggressive spam filters were a terrible idea, and deleted the suggestion altogether, saying “the suggestion was not actionable by the owners of the Suggestion Board.”

Yahoo may think weblogs are a bad idea too, as that’s exactly where Dalka took his cause. He said, “If this is going to be the normal procedure of Yahoo Suggestions, I now have serious concerns about the success of the Yahoo Suggestions initiative.”