Last year, Google launched a new design for the desktop version of Gmail along with a long-awaited overhaul and a direct placement for the Tasks app. This was accompanied by dedicated apps for Google Tasks on Android and iOS so that you can find and manage your Tasks from different devices in a single place. Google Tasks on Gmail's desktop version also allows adding important e-mails to your list of daily tasks and now, this functionality is being carried over to the Gmail app on Android.
To add an e-mail to your shortlist of Google Tasks via the Android app, tap on the 3-dot menu inside any received email. Tap on the option for "Add to Tasks" at the bottom of the list to insert the message into the list of Tasks. To use the feature, you must have the Google Tasks app installed on your Android device. In case, you don't have it, you'll be directed to Play Store when you tap on the option.
When the message is added to your list of Tasks, a toast message is shown at the bottom to confirm that you've had success. You can tap on "View" to open the listing in the Tasks app. Just like other items, you can add details, a deadline, and subtasks for the objectives. Underneath, there's a button that is hyperlinked to the mail and takes you directly to it.
This seems to be another step from Google to boost the usage of the Tasks app as Google plans to make the central hub for all reminders and alerts. Since the last year, it has received over one million downloads from Android users but these numbers can be expected to shoot up once users get to learn about this new functionality. However, I wish Google integrated this with the Snooze feature in Gmail as it might have made easier to view postponed emails from a single app.
The new feature has begun rolling out for both GSuite as well as Gmail users. While this appears to be a server-side switch, make sure you have the latest version of the Gmail app on your Android phone to be able to use it.