The Premium version should allow sending emails with task details
With Todoist Premium you can send email to your projects and include labels, due dates and even reminders within the email's subject line or body.
Please refer to this blog post for more details about this feature: http://todoist.com/blog/2013/01/zero-inbox-policy-with-todoist/
Thank you David, what I would like to do is send a mail to a third person with one task of my project. And I believe that I cannot do this with the Premium version, and I find this limitative.
Sorry for the misunderstanding. Indeed, it's not possible to send tasks out of Todoist via email.
If you're usually working in a team and would like to invite people to projects, assign tasks directly to them, share updates and more, we recommend our team-based project management tool https://wecoist.com