When I click a link in an email while Firefox is not currently running, Firefox is launched, which opens a window with a blank tab, then a second window opens with the contents of the linked page. I want the link to open in the already open window when Firefox launches, and into that homepage blank tab. I have tried various permutations of the about:config settings for browser.link but nothing seems to fix this problem. If Firefox is currently running, the link opens in a new tab, which is good. But if the current tab is empty, it should open in that tab, so I don't need to close the blank tab.