ForthWrite

Overview

ForthWrite is an AI email writer that drafts replies in your unique voice across Gmail and Outlook. It learns how you write by comparing every AI draft to what you actually sent, using that gap as a training signal. Over time, drafts get closer to your tone, sentence rhythm, and sign-offs, requiring less editing. Built for professionals, sales teams, founders, and consultants who spend hours on one-to-one email and want replies that sound authentically theirs without manual rewriting.

Key Features

Voice Match: Analyzes your sent emails to capture tone, sentence rhythm, and sign-offs, then progressively learns these traits to mimic your writing style.
Auto-Draft & Batch Drafting: Writes replies in the background as email lands and drafts dozens of threads in parallel so drafts wait for you when you open your inbox.
Prompt Lab: Lets you manage and test prompts against your previously sent emails, with suggestions for revisions based on your real data.
Multi-Model Support (BYOK): Choose from 9 AI providers including OpenAI, Anthropic, Google, xAI, DeepSeek, Mistral, Perplexity, Cohere, and Groq instead of being locked to one model.
Analytics Dashboard: Tracks acceptance rate, similarity score, edit-distance, and time saved so you can see drafts improve week over week.
RAG-Powered Personalization (Pro): Pulls your most relevant past replies as live examples when drafting new emails, making outputs smarter and more like you over time.
Gmail and Outlook Integration: Works through a Chrome extension in Gmail and Outlook Web, with a native Add-in available from Microsoft AppSource for Outlook desktop.
No M365 Copilot Required: Runs inside Outlook Web without requiring a Microsoft 365 Copilot license for personal accounts.

Pros

Personalized Voice Matching: Learns from your actual sent emails rather than generic templates, so drafts feel authentic instead of robotic.
No Setup or Training Needed: Starts working immediately after install with no manual training, prompt engineering, or onboarding required.
Model Flexibility with BYOK: Bring your own API key from 9 providers and get a roughly 17% discount on paid plans.
Free Tier Available: 10 AI drafts per week at no cost, with voice matching included and no credit card required to start.
60-Day Voice Guarantee: If drafts do not sound like you within 60 days, the team will tune your profile on a call or refund your purchase.
Works in Existing Inbox: No new app to learn since it lives inside Gmail and Outlook through a Chrome extension.

Cons

Not Built for Marketing Campaigns: Does not handle email automation, list segmentation, or campaign performance metrics since it focuses on one-to-one communication.
Chrome Extension Dependency: Outlook Web users need Chrome or Edge to use the extension, which may limit users tied to other browsers.
Limited Free Plan: 10 drafts per week may not be enough for heavy email users to fully evaluate the tool before upgrading.
Voice Quality Improves Over Time: Early drafts may need more editing while the system learns your style from your sent items.
Paid Plan Required for Advanced Personalization: RAG-powered personalization that pulls from your past replies is locked behind the Pro tier.

Use Cases

Sales outreach and follow-ups: Sales professionals can batch draft personalized replies to prospects and clients, keeping the voice consistent across dozens of threads without spending hours per day in the inbox.
Agency client communication: Agency owners and account managers handling multiple client conversations can produce on-brand replies that sound like them, reducing the time spent rewriting AI-generated drafts.
Founder and executive email: Busy founders can clear their inbox faster by having drafts ready when they open Gmail, while keeping the personal tone investors and partners expect.
Recruiting and candidate outreach: Recruiters can send warm, personalized candidate messages at scale without the templated feel that hurts response rates.
Customer success replies: Customer success managers handling repetitive but nuanced inquiries can rely on auto-draft to prepare responses that still sound personal to each customer.
Consulting client correspondence: Independent consultants juggling several clients can keep written communication consistent in their voice across different engagements and industries.

Frequently Asked Questions

How does ForthWrite learn my writing style?

ForthWrite analyzes your sent emails to capture your tone, sentence rhythm, greetings, and sign-offs. Every time you edit an AI draft, it compares the original to what you actually sent and uses that gap as a training signal so future drafts get closer to your voice.

Does ForthWrite work with Outlook?

Yes. It works inside Outlook Web through a Chrome extension that activates when you load Outlook in Chrome or Edge, with no Microsoft 365 Copilot license required for personal accounts. For desktop users, there is also a native Add-in available from Microsoft AppSource.

What does the free plan include?

The free plan gives you 10 AI-generated drafts per week with voice matching included. No credit card or API key is required to start.

What is the difference between Standard and Pro?

Standard includes unlimited drafts, a custom persona prompt, intent-aware coaching, and a more capable AI model. Pro adds RAG-powered personalization, which pulls your most relevant past replies as live examples when writing new drafts.

Is ForthWrite an email marketing tool?

No. ForthWrite is an inbox assistant for one-to-one communication and does not manage campaigns, list segmentation, automation sequences, or campaign metrics.

What is the 60-day voice guarantee?

If your drafts do not sound like you within 60 days, the ForthWrite team will personally tune your voice profile and prompts on a call. If you are still not satisfied, they will refund your purchase.