At this moment, this feature is only available in the Proton Mail V4 Beta app. Since it's currently under development, you need to join the Beta Testing Program for Proton Mail for Play Store allows you to install it on your device. You can see how to do that at https://support.google.com/googleplay/answer/7003180?hl=en

I've been using it for quite a few weeks and it's getting better and better every time.

I hope it helps!

Yeah this is something that should've been available out of the box.

Though even the desktop one needs work, sometimes includes unrelated convos with same subject from prior years.

This is a deal breaker. 7 years since the original request, this is unbelievable

I came to Proton with the goal of fully switching from Google, but the mobile inbox on android is almost unusable due to the lack of conversation view/threading. Not only is it frustrating, it makes me hesitant to invest in any of the paid plans if very basic features like this are missing for 7+ years

Please add this basic functionality!

Completely agree. This is a basic function. I hate that I have 5, 10, 20 different emails from the same conversation.

This singular issue will define whether or not I continue using Proton Mail.

Any Android owner who uses Proton Mail primarily on mobile is overwhelmed with messages organized in a poor format that makes search difficult, drafts and replies challenging, and management nearly impossible. This is basic functionality.

Please implement the same changes for Android that you implement for IOS, starting with Conversation View.

Thank you.