
Microsoft Outlook
Mailbird
eM Client
Postbox
Mailspring
Apple Mail
ProtonMail
Thunderbird is a free email application that's easy to set up and customize - and it's loaded with great features!

Fyxer
ReciteMail
MailMaestro
ReclaimAI
Flowrite
Lavender
Superhuman
Email that sounds like you, and gets measurably more like you every week. Drafts in Gmail, Outlook, and the browser. Free to start.

Which is more popular?
Website, pricing, platforms and company facts side by side.
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| Website | thunderbird.net | forthwrite.ai |
| Pricing | — | |
| Platforms | — | |
| Company | — | Startup from the United States · 1 - 9 employees · 2026 |
| Listed in |
In their own words, as submitted to SaaSHub.


No description of Thunderbird yet.
ForthWrite is an AI email writing assistant for Gmail and Outlook that learns your writing style from your real sent mail. The more you use it, the more it sounds like you. Get smart drafts in seconds, auto-draft replies before you open your inbox, and maintain your personal voice at scale. Free...
What each product offers, as listed by its team.


Possible disadvantages
An editorial look at what each product does well and who it suits.


No analysis of Thunderbird yet.
Overall verdict
Why this product is good
Recommended for
Walkthroughs and reviews on video.
Thunderbird Review Holiday World Launched Wing Coaster
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How often each product is chosen within a category, 0–100% relative to the other.


As answered by people managing Thunderbird and ForthWrite.
ForthWrite's answer:
Next.js, React, Supabase, Anthropic Claude, OpenAI, Stripe, Vercel, Chrome Extensions API
ForthWrite's answer:
ForthWrite learns your writing style from your actual sent mail, not a generic prompt. Every draft sounds like you wrote it because it was trained on how you actually write. It also auto-drafts replies before you open your inbox, so your email is partially handled before your day starts.
ForthWrite's answer:
Most AI email tools give you a blank box and a "write for me" button. ForthWrite builds a voice profile from your sent history and gets more accurate with every draft you edit or send. Unlike ChatGPT or Gemini, it works natively inside Gmail and Outlook with no copy-paste. Unlike Lavender, it writes the draft, not just scores it.
ForthWrite's answer:
Professionals who send high volumes of relationship-critical email and cannot afford to sound generic: lawyers, financial advisors, recruiters, account executives, consultants, and founders managing their own inbox.
ForthWrite's answer:
Built out of frustration with AI writing tools that produce text that sounds nothing like the person sending it, and as a way to handle large amounts of daily email. The core insight was that your sent mail is the best training data you already have, and no tool was using it.
Share your experience with using Thunderbird and ForthWrite. For example, how are they different and which one is better?
External articles and on-site reviews we used to compare the two products.


Mozilla Thunderbird is an open-source email client developed by the Mozilla community. For people who like having their email offline, a range of customization options, robust data protection and privacy features, and...
Thunderbird’s interface takes a hint from Mozilla Firefox and other popular browsers and lets you open multiple emails in separate tabs. There are a lot of options to customize the look and feel of your inbox, as well...
Thunderbird is an open-source, cross-platform email suite. It is one of the best Mac mail applications that provides easy to use wizard for setting account. This software helps you to personalize the email the way you...
I built ForthWrite because I kept sending emails that sounded like they came from the same generic AI as everyone else. After launching it, I still use it for my own inbox every day, which is about the most honest...
When comparing Thunderbird and ForthWrite, you can also consider the following products.

Organize your world. Outlook’s email and calendar tools help you communicate, stay on top of what matters, and get things done.
Compare Microsoft Outlook to Thunderbird or ForthWrite:

Rewrite or polish any email in seconds. Fyxer’s free AI email rewriter fixes your tone, grammar and flow to sound professional. No signup to try.
Compare Fyxer to Thunderbird or ForthWrite:

Mailbird is the best email client for Windows 7, 8 and 10
Compare Mailbird to Thunderbird or ForthWrite:

You answer the same emails over and over. ReciteMail drafts the reply in your voice, in seconds, on your own machine.
Compare ReciteMail to Thunderbird or ForthWrite:

eM Client is a fully-featured email client for Windows and macOS with a clean and easy-to-use interface. eM Client also offers features for calendars, tasks, contacts, notes, and chat.
Compare eM Client to Thunderbird or ForthWrite:

MailMaestro: your AI email assistant. Summarize email threads and attachments, easily find available meeting times with AI, draft high-quality emails -- all done securely within seconds.
Compare MailMaestro to Thunderbird or ForthWrite: