When you want to add task using email it says that you must select the task first even though you have already done this. What it actually wants you to do is to maximise the window of that email and then you can add the task using Todoist app. Selecting the line for the email from the window is not sufficient. I believe this is a fault with the Todoist app. Also, the app doesn't allow to right click the email row/header from the folder and then select "todoist" as a menu option from the short cut menu. This option would be more useful.