MailRules vs Inbox Zero
Both let you write email rules in plain English, and both can be self-hosted. Inbox Zero is a full AI assistant for Gmail and Outlook; MailRules does one job, sorting, on any IMAP mailbox.
| MailRules | Inbox Zero | |
|---|---|---|
| Mail providers | Any IMAP mailbox with an app password: iCloud, Fastmail, Yahoo, Zoho, Gmail or your own server. One-click Gmail and Outlook sign-in is planned for every cloud plan. | Gmail and Outlook, including Microsoft 365 work and school accounts. |
| How rules are written | Type or dictate one rule or several in a paragraph. MailRules splits them into rules, flags overlaps and asks when something is unclear. Rules can also use exact conditions: sender, domain, subject, any header, attachments. | Describe how you want email handled in plain English and review the rules it generates. Conditions can be AI instructions, From/To/Subject matches, or both. |
| What a rule can do | Move, archive, trash, mark as junk, flag, mark read or unread, or keep. Nothing is ever permanently deleted, and every action can be undone for 30 days. | Label, move, archive, delete, draft or send replies, forward, mark as spam, call a webhook, add to a digest, notify Slack, Teams or Telegram, and more. |
| Model choice | Jev or Clef decision models, Anthropic, any OpenAI-compatible API, or Ollama on your own machine. Set it for all rules or per rule. | Its own included AI by default, or your own key for Anthropic, OpenAI, Azure OpenAI, Google, Groq, Cerebras, OpenRouter or Vercel AI Gateway. Self-hosted, it also supports Bedrock, Vertex AI and Ollama. |
| Self-hosting | One Go binary with SQLite. Run it with Docker, the binary or Homebrew. | Docker Compose with Postgres and Redis. The production guide asks for a VPS with at least 2 GB RAM and 2 CPU cores, plus Google or Microsoft OAuth set up by you. |
| Licence | AGPL-3.0. | AGPL-3.0 with added terms: organisations with five or more business users need an enterprise licence, and the software can't be sold as a paid service without permission. |
| Price | Self-hosting is free; you pay your model provider. Hosted cloud is coming: Personal $5 a month, Pro $10 a month, Team $8 per seat. | Hosted: $20, $35 or $50 per user a month, or $18, $28 or $42 billed yearly. Every plan has a 7-day free trial. |
Where your mail has to live
Inbox Zero connects to Gmail and Outlook. If your mail is on iCloud, Fastmail, Yahoo, Zoho or a server you run, it has no way in. MailRules connects to any IMAP mailbox with an app password and watches it with IMAP IDLE, so new mail is filed seconds after it lands. It moves mail on the server, so Apple Mail, your phone and webmail all see the same folders.
An assistant, or just the sorting
Inbox Zero labels and files mail, and it also drafts replies, sends emails, tracks follow-ups and prepares meeting briefs. MailRules only sorts. Each email takes the cheapest path that can decide it: senders you’ve corrected, then exact conditions, then a small decision model. A larger model is asked only when that one is unsure. Anything still unclear stays in your inbox and waits in Needs review. Every action shows a one-line reason and can be undone for 30 days.
Running it yourself
Both are open source. Inbox Zero’s self-hosted setup is a Next.js app with Postgres, Redis and a cron container, and you register your own Google or Microsoft OAuth app. MailRules is a single Go binary with SQLite and a web UI on localhost. It starts in dry-run mode, so you can watch what it would do before it touches your mail.
When Inbox Zero is the better pick
Pick Inbox Zero if your mail lives in Gmail or Outlook and you want more than sorting. It drafts replies in your voice, tracks emails waiting on an answer, prepares meeting briefs from your calendar, and lets you chat with your inbox from Slack, Teams or Telegram. MailRules does none of that. It only files mail, and it has no draft replies today.
Sources
Checked on 8 October 2026.
- Inbox Zero repository and README
- Inbox Zero licence
- Inbox Zero pricing
- Inbox Zero docs: introduction
- Inbox Zero docs: using Outlook
- Inbox Zero docs: AI Personal Assistant (rules and actions)
- Inbox Zero docs: use your own AI API key
- Inbox Zero docs: self-hosted LLM setup
- Inbox Zero docs: Docker/VPS deployment
Questions
Does Inbox Zero work with iCloud or Fastmail?
Its documentation lists Gmail and Outlook only. MailRules works with iCloud, Fastmail and any other IMAP mailbox that accepts an app password.
Can MailRules draft or send replies like Inbox Zero?
No. MailRules sorts mail and never sends anything. Draft replies are planned as a paid cloud feature.
Which one is lighter to self-host?
MailRules is one Go binary with SQLite. Inbox Zero runs a Next.js app with Postgres and Redis, and its guide asks for at least 2 GB of RAM.
Can I use my own AI key with both?
Yes. Both accept your own key, and both can run with Ollama on your own machine when self-hosted.
Do I have to change mail apps?
No, with either. Inbox Zero works inside Gmail or Outlook. MailRules moves mail on the server, so every app you use sees the result.