MBox Trainer — Turn Email History Into Fine-Tuning Data · MBox Trainer
Local-first training data preparation

Turn messy email history into fine-tuning data.

MBox Trainer helps you import real email conversations, process them with local or remote LLMs, review useful candidates, and prepare clean JSONL training examples — so you can see what your own archive can become before choosing a paid plan.

30-day Basic trial · No credit card required
Desktop appMBOX importMailbox syncReview workflowJSONL export
MBox Trainer desktop app workflow for turning email conversations into training examples
Import real conversations Start with MBOX files or synced mailboxes instead of hand-writing fake examples.
Find useful candidates Use processing profiles to identify conversations worth turning into training data.
Review before export Approve, reject, edit, and export only the examples that are ready for a model.
The problem

Your best training examples are probably buried in old email.

Support threads, project updates, sales replies, operations messages, and internal discussions often contain real examples of how your organization communicates. The hard part is turning that messy archive into clean, usable model data.

Email is useful, but noisy

Threads include quotes, signatures, duplicates, side chatter, private details, and half-finished conversations.

Fine-tuning needs structure

A model cannot learn much from a raw inbox dump. It needs focused prompts, useful completions, and consistent output structure.

Review still matters

The goal is not to blindly automate training data. The goal is to help you find better candidates faster and keep control before export.

How it works

A guided pipeline from inbox history to export-ready examples.

MBox Trainer gives the workflow a clear path: import the source data, process it with the right profile, review the candidates, and export the examples that are ready to use.

01

Import email data

Start with MBOX files, mailbox sources, or manual import paths.

02

Choose a profile

Use processing profiles and prompt templates to guide what the app should look for.

03

Run processing passes

Classify, clean, extract, naturalize, score, and prepare candidate examples.

04

Review the candidates

Approve, reject, edit, and understand why each candidate was suggested.

05

Export clean JSONL

Generate local training-data files that are ready for your fine-tuning workflow.

Built for practical dataset work

Less inbox archaeology. More usable examples.

The app is designed around the work between “I have old email” and “I have a dataset worth training on.”

Processing profiles

Create reusable workflows for the kinds of examples you want to find, clean, score, and export.

Prompt template control

Tune the instructions used for classification, extraction, privacy cleanup, quality checks, and naturalization.

Privacy cleanup

Prepare data more responsibly by cleaning sensitive details before examples move closer to export.

Candidate review

Keep the human in the loop with approval, rejection, editing, and evidence for why a candidate was created.

Local-first workflow

Use the desktop app with local or remote model endpoints depending on your workflow and comfort level.

JSONL export

Export clean training examples in a practical format for downstream fine-tuning experiments.

Pricing

Yearly plans for serious training-data work.

Start with a 30-day Basic workflow trial, then choose the yearly plan that fits your archive size, processing volume, and export workflow.

Try the Basic workflow before paying. Import, process, review, and inspect candidate training examples during the trial. Exporting finalized datasets requires an active paid subscription.
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Starter

For solo builders validating smaller email-to-dataset workflows.

$120/year

  • 2 projects
  • 2 import sources
  • 1 GB max MBOX file size
  • 2,000 conversations processed / month
  • 25 processing runs / month
  • 1,000 training examples / month
  • 10 export batches / month
  • 250 conversations / run
  • Manual sync
Most popular

Basic

For regular dataset-building work across multiple projects.

$240/year

  • 30-day Basic workflow trial available
  • 10 projects
  • 10 import sources
  • 3 GB max MBOX file size
  • 10,000 conversations processed / month
  • 200 processing runs / month
  • 5,000 training examples / month
  • 50 export batches / month
  • 1,000 conversations / run
  • Scheduled sync every 60 minutes

Pro

For larger archives, heavier processing, and faster sync workflows.

$590/year

  • 50 projects
  • 50 import sources
  • 10 GB max MBOX file size
  • 50,000 conversations processed / month
  • 2,000 processing runs / month
  • 25,000 training examples / month
  • 250 export batches / month
  • 5,000 conversations / run
  • Scheduled sync every 15 minutes

Yearly pricing shown. Monthly billing options may be available at checkout. The Basic workflow trial lets you test importing, processing, and reviewing candidate examples before paying.

Exporting finalized datasets requires an active paid plan. Remote model usage may require separate provider/API costs depending on the endpoint you configure.

Build better training data

Try MBox Trainer with your own email archive.

Download the desktop app, run the Basic workflow trial, and see whether your old conversations can become useful training examples before choosing a paid plan.

You can import, process, review, and inspect candidate examples during the trial. Exporting finalized datasets requires an active paid subscription.