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# Thunderbird vs eM Client Comparison - What are their main differences?

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Reviews

**Thunderbird** [

4.3/5(340)

](https://www.g2.com/products/thunderbird/reviews#reviews)

**eM Client** [

4/5(61)

](https://www.g2.com/products/em-client/reviews#reviews)

Pricing

**Thunderbird**
No pricing available

**eM Client**
Free Trial

**FREE** for Individuals · eM Client Free License

**Pricing Insights**
from reviews

Time to Implement

**Thunderbird**
1 month

Based on 30 responses

**eM Client**
Not enough reviews yet

Return on Investment

**Thunderbird**
9 months

Based on 17 responses

**eM Client**
Not enough reviews yet

Perceived Cost

**Thunderbird**
$$$$$

**eM Client**
$$$$$

Average Discount

**Thunderbird**
13%

**eM Client**
Not enough reviews yet

Pros & Cons

**Thunderbird**
[
Ease of Use (4)
](https://www.g2.com/products/thunderbird/reviews?filters%5Bsentiment_snippet%5D=1225855&qs=pros-and-cons#reviews)[
Functionality Features (4)
](https://www.g2.com/products/thunderbird/reviews?filters%5Bsentiment_snippet%5D=1225521&qs=pros-and-cons#reviews)[
Difficult Setup (2)
](https://www.g2.com/products/thunderbird/reviews?filters%5Bsentiment_snippet%5D=2064059&qs=pros-and-cons#reviews)[
Missing Features (2)
](https://www.g2.com/products/thunderbird/reviews?filters%5Bsentiment_snippet%5D=2230822&qs=pros-and-cons#reviews)

**eM Client**
[
Ease of Use (2)
](https://www.g2.com/products/em-client/reviews?filters%5Bsentiment_snippet%5D=2245078&qs=pros-and-cons#reviews)[
User Interface (2)
](https://www.g2.com/products/em-client/reviews?filters%5Bsentiment_snippet%5D=2245070&qs=pros-and-cons#reviews)[
Lack of Integration (1)
](https://www.g2.com/products/em-client/reviews?filters%5Bsentiment_snippet%5D=2245094&qs=pros-and-cons#reviews)[
Missing Features (1)
](https://www.g2.com/products/em-client/reviews?filters%5Bsentiment_snippet%5D=2245043&qs=pros-and-cons#reviews)

Integrations

**Thunderbird**
Not enough data

**eM Client**
[

 ![Product Avatar Image](https://images.g2crowd.com/uploads/product/image/large_detail/large_detail_e79ca793b5194435a820f255cea120d4/goto-meeting.png "Product Avatar Image")

GoTo Meeting

](https://www.g2.com/products/goto-meeting/reviews)[

 ![Product Avatar Image](https://images.g2crowd.com/uploads/product/image/large_detail/large_detail_76301329f5d8e64a29ec622cecb5e45f/icewarp.png "Product Avatar Image")

IceWarp

](https://www.g2.com/products/icewarp/reviews)[

 ![Product Avatar Image](https://images.g2crowd.com/uploads/product/image/large_detail/large_detail_ae5d46296d0f8afa0fd352fc44bf419d/microsoft365.png "Product Avatar Image")

Microsoft 365

](https://www.g2.com/products/microsoft365/reviews)[

 ![Product Avatar Image](https://images.g2crowd.com/uploads/product/image/large_detail/large_detail_218a6468d313312e43446d6a8135f441/microsoft-teams.png "Product Avatar Image")

Microsoft Teams

](https://www.g2.com/products/microsoft-teams/reviews)[
View all
](https://www.g2.com/products/em-client/integrations)

Screenshots

**Thunderbird**
No screenshot available

**eM Client**
 ![eM Client screenshot](https://images.g2crowd.com/cdn-cgi/image/width=600,height=600,fit=scale-down,format=auto,onerror=redirect,/https://images.g2crowd.com/uploads/attachment/file/177643/main-messages.png)

Ratings

Meets Requirements

**Thunderbird**

8.7

8.7305

**eM Client**

8.5

8.548

Ease of Use

**Thunderbird**

8.8

8.8306

**eM Client**

8.8

8.850

Ease of Setup

**Thunderbird**

8.8

8.876

**eM Client**

9.5

9.510

Ease of Admin

**Thunderbird**

8.4

8.458

**eM Client**

8.1

8.17

Quality of Support

**Thunderbird**

7.9

7.9222

**eM Client**

7.8

7.842

Has the product been a good partner in doing business?

**Thunderbird**

8.1

8.141

**eM Client**

7.8

7.86

Product Direction (% positive)

**Thunderbird**

7.7

7.7303

**eM Client**

9.0

9.046

Features

Email Client[Hide 11 FeaturesShow 11 Features](javascript:void(0);)

8.5

124

8.5

23

Inbox Tools

Unified Inbox

8.9(won by 0.4)

104

8.5

20

Filters

9.0(won by 0.2)

110

8.8

21

Reminders

8.5(won by 0.2)

97

8.3

20

Notifications

8.7(won by 0.4)

105

8.3

20

Coordination Tools

Calendar

8.5

94

8.8(won by 0.3)

22

Contacts

8.6(won by 0.3)

102

8.3

21

Task Management

8.4(won by 0.1)

89

8.3

17

Software Options

Desktop Application

9.2(won by 0.3)

111

8.9

22

Mobile Application

7.6(won by default)

65

Feature Not Available

Email Client - Agentic AI

Cross-system Integration

8.0(won by default)

5

Not enough data

Autonomous Task Execution

Not enough data

Not enough data

Email Management[Hide 62 FeaturesShow 62 Features](javascript:void(0);)

8.9

10

Not enough data

Sorting & Filtering

Attachment Search

9.2(won by default)

6

Not enough data

Tags

9.8(won by default)

8

Not enough data

AI Sorting

8.0(won by default)

5

Not enough data

Predefined Rules

9.2(won by default)

6

Not enough data

Integrations

Microsoft Outlook Integration

8.3(won by default)

6

Not enough data

Gmail Integration

9.0(won by default)

7

Not enough data

Apple Calendar Integration

8.1(won by default)

6

Not enough data

Social Media Integration

Not enough data

Not enough data

Third-Party Integrations

Not enough data

Not enough data

Time Management

Unified Inbox

9.4(won by default)

6

Not enough data

Email Automation

8.8(won by default)

7

Not enough data

Snooze

9.0(won by default)

5

Not enough data

Generative AI

AI Text Generation

Not enough data

Not enough data

AI Text-to-Speech

Not enough data

Not enough data

AI Text Summarization

Not enough data

Not enough data

Generative AI

Not enough data

Not enough data

Agentic AI - Email Management

Autonomous Task Execution

Not enough data

Not enough data

Cross-system Integration

Not enough data

Not enough data

Additional Functionality

Whitelisting/Blacklisting

Not enough data

Not enough data

Customizable Fields

Not enough data

Not enough data

Signature Management

Not enough data

Not enough data

Shared Inboxes

Not enough data

Not enough data

Email Distribution

Not enough data

Not enough data

Prioritization

Not enough data

Not enough data

Customizable Forms

Not enough data

Not enough data

AI Copilot

Not enough data

Not enough data

Mobile App

Not enough data

Not enough data

Routing

Not enough data

Not enough data

Activity Dashboard

Not enough data

Not enough data

Collaboration Tools

Not enough data

Not enough data

Inbox Management

Not enough data

Not enough data

Queue Management

Not enough data

Not enough data

Drag & Drop

Not enough data

Not enough data

Contact Management

Not enough data

Not enough data

Email Marketing

Not enough data

Not enough data

Data Recovery

Not enough data

Not enough data

Archiving & Retention

Not enough data

Not enough data

Real-Time Monitoring

Not enough data

Not enough data

Autoresponders

Not enough data

Not enough data

Multiple User Accounts

Not enough data

Not enough data

API

Not enough data

Not enough data

Real-Time Analytics

Not enough data

Not enough data

Customer Segmentation

Not enough data

Not enough data

Search/Filter

Not enough data

Not enough data

Support Ticket Management

Not enough data

Not enough data

Canned Responses

Not enough data

Not enough data

Workflow Management

Not enough data

Not enough data

Reporting/Analytics

Not enough data

Not enough data

Chat/Messaging

Not enough data

Not enough data

Response Management

Not enough data

Not enough data

Email Templates

Not enough data

Not enough data

Email Monitoring

Not enough data

Not enough data

Campaign Management

Not enough data

Not enough data

Email Tracking

Not enough data

Not enough data

Access Controls/Permissions

Not enough data

Not enough data

Spam Blocker

Not enough data

Not enough data

Alerts/Notifications

Not enough data

Not enough data

Customizable Templates

Not enough data

Not enough data

Real-Time Reporting

Not enough data

Not enough data

Tagging

Not enough data

Not enough data

Campaign Analytics

Not enough data

Not enough data

Workflow Automation

Not enough data

Not enough data

Show 1 feature category with incomplete data

Collaboration & Productivity[Hide 45 FeaturesShow 45 Features](javascript:void(0);)

Not enough data

Not enough data

Additional Functionality

Third-Party Integrations

Not enough data

Not enough data

To-Do List

Not enough data

Not enough data

@mentions

Not enough data

Not enough data

Single Sign On

Not enough data

Not enough data

File Management

Not enough data

Not enough data

Activity Dashboard

Not enough data

Not enough data

Drag & Drop

Not enough data

Not enough data

Alerts/Notifications

Not enough data

Not enough data

Prioritization

Not enough data

Not enough data

Access Controls/Permissions

Not enough data

Not enough data

Screen Sharing

Not enough data

Not enough data

Content Management

Not enough data

Not enough data

Brainstorming

Not enough data

Not enough data

AI Copilot

Not enough data

Not enough data

File Transfer

Not enough data

Not enough data

Calendar Management

Not enough data

Not enough data

Status Tracking

Not enough data

Not enough data

Real-Time Notifications

Not enough data

Not enough data

Version Control

Not enough data

Not enough data

Task Management

Not enough data

Not enough data

Activity Tracking

Not enough data

Not enough data

Real Time Editing

Not enough data

Not enough data

Communication Management

Not enough data

Not enough data

Chat/Messaging

Not enough data

Not enough data

Tagging

Not enough data

Not enough data

Generative AI

Not enough data

Not enough data

Assignment Management

Not enough data

Not enough data

Task Scheduling

Not enough data

Not enough data

Project Management

Not enough data

Not enough data

Collaboration Tools

Not enough data

Not enough data

Workflow Management

Not enough data

Not enough data

Secure Data Storage

Not enough data

Not enough data

File Sharing

Not enough data

Not enough data

Document Storage

Not enough data

Not enough data

Task Progress Tracking

Not enough data

Not enough data

Discussions/Forums

Not enough data

Not enough data

Commenting/Notes

Not enough data

Not enough data

Reporting & Statistics

Not enough data

Not enough data

Contact Management

Not enough data

Not enough data

Video Conferencing

Not enough data

Not enough data

Progress Tracking

Not enough data

Not enough data

Mobile Access

Not enough data

Not enough data

API

Not enough data

Not enough data

Document Management

Not enough data

Not enough data

Customizable Branding

Not enough data

Not enough data

User Insights

Reviewers' Company Size

[![Thunderbird](https://images.g2crowd.com/uploads/product/image/thumb_square/thumb_square_6ca5b57b63c45814e9ef66a64ca43c19/thunderbird.png "Thunderbird")](https://www.g2.com/products/thunderbird/reviews)

Thunderbird

Small-Business(50 or fewer emp.)

65.2%

Mid-Market(51-1000 emp.)

24.3%

Enterprise(\> 1000 emp.)

10.5%

[![eM Client](https://images.g2crowd.com/uploads/product/hd_favicon/279347ac57ba92081663a3e86d7b6132/em-client.svg "eM Client")](https://www.g2.com/products/em-client/reviews)

eM Client

Small-Business(50 or fewer emp.)

46.4%

Mid-Market(51-1000 emp.)

35.7%

Enterprise(\> 1000 emp.)

17.9%

Small-Business

(50 or fewer emp.)

65.2%

46.4%

Mid-Market

(51-1000 emp.)

24.3%

35.7%

Enterprise

(\> 1000 emp.)

10.5%

17.9%

Reviewers' Industry

[![Thunderbird](https://images.g2crowd.com/uploads/product/image/thumb_square/thumb_square_6ca5b57b63c45814e9ef66a64ca43c19/thunderbird.png "Thunderbird")](https://www.g2.com/products/thunderbird/reviews)
Thunderbird

Information Technology and Services

12.9%

Computer Software

11.7%

Internet

6.6%

Marketing and Advertising

5.1%

Telecommunications

3.3%

Other

60.4%

[![eM Client](https://images.g2crowd.com/uploads/product/hd_favicon/279347ac57ba92081663a3e86d7b6132/em-client.svg "eM Client")](https://www.g2.com/products/em-client/reviews)
eM Client

Information Technology and Services

38.6%

Computer Software

19.3%

Marketing and Advertising

7.0%

Industrial Automation

5.3%

Retail

3.5%

Other

26.3%

FAQs

## Thunderbird vs eM Client FAQs

Generated using AI

Last updated: August 14, 2026

### What is the difference between Thunderbird vs eM Client?

Thunderbird stands out for its higher G2 rating, larger review volume, and open-source positioning, while eM Client is noted for its modern interface and strong calendar integration.

| | [Thunderbird](https://www.g2.com/products/thunderbird/reviews) | [eM Client](https://www.g2.com/products/em-client/reviews) |
| --- | --- | --- |
| G2 Rating (reviews) | 4.3/5 (340 reviews) | 4.0/5 (61 reviews) |
| Largest Segment | Small-Business | Small-Business |
| Ease of Setup score | 8.8 | 9.5 |
| Quality of Support score | 7.9 | 7.8 |
| Top Reviewer-Cited Strength | Ease of Use (4 all-time mentions) | User Interface (2 all-time mentions) |

### How do the pricing models of Thunderbird and eM Client compare?

Thunderbird is considered the stronger value by reviewers, with a higher satisfaction score on price and cost-related dimensions.

- **Thunderbird:** Reviewers consistently highlight Thunderbird as a free, open-source solution with strong ROI and no subscription fees.
- **eM Client:** Reviewers note that eM Client is a paid product with a limited free version, and mention the value of its lifetime license option, but also cite restrictions in the free tier and additional costs for support or upgrades.
- **Switching reasons:** Several reviewers mention switching to Thunderbird to avoid subscription costs and to gain more flexibility compared to paid alternatives.

### What are the best alternatives to Thunderbird and eM Client?

The top 3 alternatives to Thunderbird and eM Client are Outlook, Front, and Spike.

| Product | G2 Rating (reviews) | Largest Segment | Pricing Insight | Top Reviewer-Cited Strength |
| --- | --- | --- | --- | --- |
| [Thunderbird](https://www.g2.com/products/thunderbird/reviews) | 4.3/5 (340 reviews) | Small-Business | Free, open-source, strong ROI | Ease of Use (4 all-time mentions) |
| [eM Client](https://www.g2.com/products/em-client/reviews) | 4.0/5 (61 reviews) | Small-Business | Paid, limited free version, lifetime license available | User Interface (2 all-time mentions) |
| [Outlook](https://www.g2.com/products/microsoft-outlook/reviews) | 4.5/5 (3,523 reviews) | Enterprise | — | Integration with Microsoft ecosystem |
| [Front](https://www.g2.com/products/front/reviews) | 4.7/5 (2,507 reviews) | Small-Business | — | Team collaboration features |
| [Spike](https://www.g2.com/products/spike/reviews) | 4.6/5 (262 reviews) | Small-Business | — | Conversational email interface |

### Which Email Client features should I prioritize when comparing Thunderbird and eM Client?

Buyers should prioritize ease of setup, calendar functionality, user interface, inbox management, and integration capabilities when comparing Thunderbird and eM Client.

- **Ease of Setup:** eM Client scores 9.5, Thunderbird scores 8.8.
- **Calendar Functionality:** Calendar is the most frequently mentioned feature; both products are praised for integrated calendar management.
- **User Interface:** eM Client has 2 all-time mentions for user interface, Thunderbird has 4 for ease of use.
- **Inbox Management:** Thunderbird has 2 all-time mentions for inbox management, eM Client is noted for unified inbox and advanced search.
- **Integration Capabilities:** eM Client is cited for integration with platforms like IceWarp; Thunderbird is praised for cross-platform compatibility and add-ons.

### What are the pros and cons of Thunderbird vs eM Client?

Thunderbird's headline strength is its ease of use and open-source flexibility, while eM Client is recognized for its modern interface and integrated calendar.

- **Thunderbird strengths:** Ease of use (4 all-time mentions), functionality features (4), inbox management (2), security (2), cross-platform compatibility (1), and strong customization via add-ons.
- **Thunderbird trade-offs:** Difficult setup (2), missing features (2), sync issues (2), and occasional confusing interface (1).
- **eM Client strengths:** User interface (2 all-time mentions), intuitive design, integrated calendar and task management, and advanced search.
- **eM Client trade-offs:** Lack of integration (1), missing features (1), sync issues (1), and limitations in the free version.

### Is Thunderbird or eM Client better for small businesses?

Thunderbird is the better fit for small businesses, supported by its dominant small-business segment and reviewer sentiment on cost and flexibility.

- **Thunderbird:** Small-Business is the largest segment; reviewers highlight its free, open-source model and ease of managing multiple accounts for business use.
- **eM Client:** Small-Business is also the largest segment; reviewers appreciate its unified inbox and calendar, but note the paid model and free version limitations as considerations for small teams.

### Which Email Client platform has better integrations?

Thunderbird and eM Client are at parity for integrations, with each product supporting key integrations but limited recent reviewer-cited third-party tools.

- **Thunderbird:** Reviewers highlight cross-platform compatibility and add-on ecosystem, but do not cite specific third-party integrations in recent reviews.
- **eM Client:** Recent reviews mention integration with IceWarp and strong support for Exchange, IMAP, and Google accounts.

### How do Thunderbird and eM Client compare on customer support?

Thunderbird and eM Client are at parity on Quality of Support, with scores of 7.9 and 7.8 respectively, below the materiality threshold.

- **Thunderbird:** Reviewers describe support as community-driven and responsive for an open-source product, with some noting the absence of a dedicated support team.
- **eM Client:** Reviewers report prompt and helpful support experiences, especially for paid users, but mention that support for the free version is limited or requires additional payment.

### Which is easier to implement, Thunderbird or eM Client?

eM Client leads on Ease of Setup with a score of 9.5 versus Thunderbird's 8.8, a difference above the materiality threshold.

- **Thunderbird:** Reviewers note straightforward installation and configuration, but mention a learning curve for advanced features and occasional manual setup requirements.
- **eM Client:** Reviewers consistently praise its simple, intuitive setup process and automatic account configuration, with minimal technical barriers for new users.

### Which product has better Calendar?

Thunderbird and eM Client both offer strong Calendar functionality, with reviewers highlighting robust integration and usability.

- **Thunderbird:** Calendar is frequently mentioned in reviews as a core feature; reviewers praise its recurring event handling, standards-based invites, and integration with email and tasks.
- **eM Client:** Calendar is cited as a key strength, with reviewers noting seamless integration with Google Calendar, Exchange, and built-in scheduling features.

Alternatives

**Thunderbird Alternatives**

 ![Front](https://images.g2crowd.com/uploads/product/hd_favicon/1fe01c88159eb52ed7e93d98cdce08a5/front.svg "Front")

[
Front
](/products/front/reviews)

 ![Spike](https://images.g2crowd.com/uploads/product/hd_favicon/ad8d6b14c633bf13965f58ef40a77f0f/spike.svg "Spike")

[
Spike
](/products/spike/reviews)

 ![Mailbird](https://images.g2crowd.com/uploads/product/image/thumb_square/thumb_square_53eb6f8d708e7c322d572e28b89709cc/mailbird.png "Mailbird")

[
Mailbird
](/products/mailbird/reviews)

 ![BlueMail](https://images.g2crowd.com/uploads/product/image/thumb_square/thumb_square_ea674f9d92a760d473952ccec1d4bc02/bluemail.jpg "BlueMail")

[
BlueMail
](/products/bluemail/reviews)

**eM Client Alternatives**

 ![Microsoft Outlook](https://images.g2crowd.com/uploads/product/hd_favicon/5c440ee40ed0f9d1e1c0575dbdd12898/microsoft-outlook.png "Microsoft Outlook")

[
Outlook
](/products/microsoft-outlook/reviews)

 ![Spike](https://images.g2crowd.com/uploads/product/hd_favicon/ad8d6b14c633bf13965f58ef40a77f0f/spike.svg "Spike")

[
Spike
](/products/spike/reviews)

 ![Mailbird](https://images.g2crowd.com/uploads/product/image/thumb_square/thumb_square_53eb6f8d708e7c322d572e28b89709cc/mailbird.png "Mailbird")

[
Mailbird
](/products/mailbird/reviews)

 ![BlueMail](https://images.g2crowd.com/uploads/product/image/thumb_square/thumb_square_ea674f9d92a760d473952ccec1d4bc02/bluemail.jpg "BlueMail")

[
BlueMail
](/products/bluemail/reviews)

## Thunderbird vs eM Client

When assessing the two solutions, reviewers found them equally easy to use. However, eM Client is easier to set up , while reviewers preferred administration and ease of doing business with Thunderbird overall.

- Reviewers felt that Thunderbird meets the needs of their business better than eM Client.
- When comparing quality of ongoing product support, reviewers felt that Thunderbird is the preferred option.
- For feature updates and roadmaps, our reviewers preferred the direction of eM Client over Thunderbird.