https://blog.asana.com/2013/03/walking-the-email-bridge/ demonstrates how to reply to a notification email to create a task comment. This is useful to keep both internal Asana users and external (email-using) contacts informed without duplicating effort (can simply send a single email with CC to task address instead of copying a comment into an email or vice versa). However, the Reply-To: address of a notification email appears to be the only place to access the appropriate task-specific email address, which entails having notifications turned on and some activity to generate a notification. At least https://asana.com/guide/help/email/email-to-asana doesn’t mention any other means.
It would be great to be able to retrieve the task-specific email Reply-To address from the web GUI for this purpose.