Apple today has released an update to OS X Yosemite’s official Mail application via Software Update in the Mac App Store. It’s available for both developers and customers on the public beta. Apple says that the update fixes an issue related to users being unable to compose messages. It’s interesting that Apple issued this update as a standalone fix versus an entirely new developer preview. Apple released new developer and public betas for Yosemite last week. The final OS is expected to ship in late October.