Thunderbird: Mark all drafts as read

I wasted like 60 seconds a day marking drafts in Thunderbird as read after using the SendLater-Plugin. The following AutoIt-Scripts that runs in background now saves this precious amount of time!

$x_offset = 80
$y_offset = 140

TraySetIcon('C:\Program Files (x86)\Mozilla Thunderbird\thunderbird.exe', 1)

While 1
    WinWait('[TITLE:Send this email later; CLASS:MozillaDialogClass]')
    WinWaitActive('[REGEXPTITLE:Mozilla Thunderbird]')
    Sleep(1000)
    $tb_pos = WinGetPos('[REGEXPTITLE:Mozilla Thunderbird]')
    $mouse_pos = MouseGetPos()
    MouseClick('right', $tb_pos[0]+$x_offset, $tb_pos[1]+$y_offset, 1, 0)
    Send('{UP 4}{ENTER}')
    MouseMove($mouse_pos[0], $mouse_pos[1], 0)
WEnd