I add a email task on Thunderbird, then I open my account on web site and I can't open that email ! why ?
When creating a task with one of our plugins, such as Outlook, or Thunderbird, or Chrome Extension, that email needs to be opened with that application.
We will try to improve this in future updates if possible.
I'm expecting it to be implemented, like a attachment file.
You can already add emails as tasks and have them accessible across all platforms if, instead of linking to them using our plugins, you send them to your projects.
Please refer to this post on our blog for more details: https://todoist.com/blog/2013/01/zero-inbox-policy-with-todoist/