Postbox issued version 4.0.6 of its eponymous email client with added support for OAuth 2 for Gmail/Google accounts and improved folder creation (with newly separate New Folder and New Sub-Folder actions). The update also fixed an issue when marking multiple messages as pending, fixed styling of the attachment Save All button on Retina displays, and improved the update experience with release notes displayed in the updater.
Shortly after that update was released, Postbox was updated to version 4.0.7, which reorganized the Compose window’s contextual menu and added an option for searching a selection in Google. Postbox 4.0.7 also now enables you to select text in the Compose window and create a Response using the contextual menu, adds Run Junk Mail Controls on Folder and Delete Mail Marked as Junk in Folder commands to the Junk toolbar button, and adds show/hide controls for headers in the Folder and Focus panes. ($15 new, free update, 25.6 MB, release notes, 10.9+)