Lark Email Collaboration

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The goal of this project is to provide users a seamless way to share, discuss and co-edit email in the Lark Email client. I worked as the product designer and I am the co-owner of the feature sets.
User Need

A seamless way to share, discuss and co-edit email.

Business Need

Competitive feature for Lark Email to acquire customers.


High NPS score, well received by internal stakeholders and users; acquired new customers.


Product Designer
Project co-owner


Email in Lark Office Suite

In 2019, we designed the email product in Lark office suite from 0 to 1.
Based on our research data, we defined email collaboration as our main product strategy and competitive feature which differentiates our email product from other email clients.

Lark Office Suite

Lark is an office suite that includes instant messaging, Docs, Calendar, and much more.

Email in Lark Office Suite

To meet users' needs and business needs, we conceptualized Lark Email and designed it from scratch.

Target Users

Use Lark for internal communication while use email for external communication.


User Goals and Scenarios

Email collaboration has been defined as a product strategy. We conducted rounds of research to validate this user need and initiate this project. Based on research data analysis, our target users would like to get their job done more efficiently. They need to communicate with different kinds of internal stakeholders and external contacts. In this process, they need to discuss emails or co-edit an email reply, as needed.

✰Persona Unit

Jane Doe

I work in the creator team of TikTok. I need to plan events with external studios using email along with my teammates and TikTok legal team.

Need: Full Control

"I need to take full control of my emails since I am the one who is responsible for them."

Need: Seamless Experience

"I would like to have a seamless way to discuss and co-edit email, with minimal steps possible."

Goal: Co-edit

"The studio sent me a list of questions. I need to co-edit the answers with team members."

Goal: Discuss

"The studio sent me contract content. I need to ask the legal team to help review it."

Pain Points

Before the collaborative features come true, our target users use Lark Message to discuss email contents with internal stakeholders and use other Email clients to communicate with external contacts. There are three main pain points they are experiencing:

Products Switching

To discuss an email, she has to forward emails or screenshot email content and send to IM groups. Once there is a new email message, she has to do it again.

Back and forth

She needs to discuss the email and co-edit response in IM groups, then put the response back to email. If it's a long response, she needs to create a doc to co-edit the response and put it back to email.

Hard to find info and sync up

Information is not organized everywhere in this situation. This makes it very difficult to sync up information with a team member or a stakeholder.

3 User Roles

After analyzing user journeys and their pain points using email products, we defined 3 user roles, which are owner, editor and viewer.

Owner - Jane

Discuss & co-edit emails with team members and legal team to get her job done efficiently.

Editor - William

As Jane’s team member, William needs to discuss & co-edit email content with Jane, to get the job done together.

Viewer - Sean

As a legal team member, Sean helps review email content and discuss to give insights or approval to Jane.


Seamless Experience to Share, Discuss and Co-edit Emails

We brainstormed ideas, prioritized concepts, and decided to provide users a seamless way to share their email thread, discuss and co-edit email within the Lark Email tab. We wanted to provide a holistic solution that provides good user experience for all three user groups.


What Collaborators Can do? Collaboration vs Privacy?

We invited target users to our design workshops, and discussed with them about what they expect in email collaboration. Based on the workshop insights, we conceptualized the permission control system as showing below.

How to Share Email Threads?

With the permission control in our mind, we designed an MVP version of Lark Email. We released it to selected target users and collected data and user feedback during a period of time. Overall, users appreciate this feature and the permission control. However, we got some new findings.

Allow Collaborators to Share Emails

For most of the cases, users would like to allow collaborators to share emails, but with their approval.

Reason: Collaborators always ask owners to add a collaborator. They need to find the specific email and  person to share. It is not convenient, especially when they are busy.

Share Emails to Lark Chat

In some cases, users would like to send email to Lark chat while sharing the emails with a collaborator/group.

Reason: When users talk about relevant events, they would like to share this email in the discussion context, so that they can continue the discussion.

Other Feedback

- Users wish to view all shared threads in a place.
- Users wish to easily recognize a shared thread in the message list.
- Users wish to control whether or not to share with external Lark users.

Design Solution

Share Email Thread

This is the very first step of email collaboration and we were very cautious about the permission control. With the user feedback in our MVP version (allow collaborators to share, share emails to Lark chat, added Shared Emails label, etc..), we redesigned the email sharing flow.

Discussion within Email

After an email thread has been shared, collaborators can discuss emails in the side panel. We hosted A/B tests on side panel discussion and in-email discussion with comment style and found that our users appreciate side panel discussion more than in-email discussion, also by integrating Lark chat components in Email discussion we are saving development time.

Co-edit Email Drafts

When it comes to co-edit email drafts, in order to protect owners' privacy while fostering collaboration, we adapted the permission control of viewing messages, co-editing drafts and sending out messages based on users' feedback from our MVP design.

Owner - Jane

Owners can do anything, especially have privilege in sending out and deleting drafts.

Editor - William

Editors can initiate drafts, co-edit drafts, but can not add recipients or send out the message.

Viewer - Sean

Viewers can view email messages and drafts, but can not edit drafts. They can request edit permission, as needed.


Platform Consistency

During this process, we developed the Lark Email design system. We defined the color palette, typography and UI styles in the early stage to ensure design consistency within Lark. There are some specific components that we need to develop for email products, e.g. the attachments, and the thread layout for different states.



The public beta release was well received by our users, and we measured the success of both the user side and the business side.

Share flow

After A/B testing, the new design brought a double-digit DAU increase.

Discuss & co-edit flow

In 78% of the shared email threads, users used discussion panel.

In 39% of the shared emails, more than 51% of users edit drafts.


Well received by users and stakeholders.

A selling point for Lark Email and helped acquire new customers.

Self Evaluation

As a Product Designer, first I tried to understand the product as much as possible: 1. Why people need email collaboration; 2. What features users need most for collaboration; 3. How can we integrate the new features into the current design seamlessly. Then with these questions in my mind, along with several rounds of user studies, I was always designing with intention, finally I was able to deliver the email collaboration features which were well received by internal stakeholders and our target users.

"Ethan (Yi) really cared about the end users, he did a really great job in problem framing and solving users’ pain points with his experience design skills. He was an intern, but his work was as good as an experienced designer. Overall, I’m still impressed by his energy, attitude and motivation as a Product Designer."
Junying Chang
Design Lead of Email & Globalization @ ByteDance USA