There are tools that support email integration. In PostFrenzy (http://postfrenzy.com), for example, you can take an email and forward it to the workspace you would like it to be placed in (the email address for a workspace can be seen at the top under its description). If you are looking to convert an email into a task you can click forward, enter the workspace's email address, edit the message (if necessary), then click send. If your workspace is already open in another tab in your browser it will automatically appear at the top of the list.