Maillifier review
A self-hosted Gmail reply-drafting agent with Gemini, attachment processing, and custom rules.
Reviewed by iTechGuides Editors · Editorial team · Updated Oct 2026
Maillifier is an open-source AI email assistant for individuals or teams who want drafted replies in a self-hosted Gmail workflow. It runs as a Google Apps Script project in the user's Google account: users forward messages to a dedicated Gmail agent account, which processes them through the Google Gemini API and returns reply drafts. That account-based approach suits people who want to keep the workflow under their own Google account rather than route inbox data through Maillifier-operated servers.
Its feature set reaches beyond plain-text drafting. Maillifier detects the language for replies and can process PDF, DOCX, XLSX, CSV, charts, and other files attached to forwarded emails. Personal AI rules can be set through email commands, while a company knowledge base is stored in Google Drive. Gmail filtering and labeling help organize the workflow, and activity is logged to Google Sheets. The connections to Gmail, Apps Script, Gemini API, Drive, and Sheets make it a fit for teams already working in Google's ecosystem; it is not positioned as an assistant spanning multiple email platforms.
The published plan is Free and identifies Maillifier as an open-source Google Apps Script project with AI-drafted replies running in the user's Google account. Using it requires a Google account and the user's own Gemini API key, and third-party Google or Gemini usage costs may apply. Access control is whitelist-based, and the workflow depends on forwarding messages to a dedicated agent account rather than operating as a general inbox assistant. Choose Maillifier if Gmail, self-hosting, attachment processing, and configurable reply behavior match your needs. Consider an alternative if you need support for email platforms beyond Gmail or an assistant that drafts without a forwarded-email workflow.
Maillifier pros and cons
- Where it wins
- Drafts replies with Google Gemini and detects the email's language
- Processes PDF, DOCX, XLSX, CSV, charts, and other attachments
- Supports personal rules, a Google Drive knowledge base, and access controls
- Where it doesn't
- Limited to a Gmail agent workflow rather than multiple email platforms
- Requires a Google account and a Google Gemini API key
- Third-party Google or Gemini usage costs may apply
Maillifier fact sheet, pricing and score →
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