Jace AI is an email agent for people whose inbox is their job. It connects to Gmail or Outlook, learns how you write from your sent mail, applies rules and AI labels that keep running once you configure them, reads whole threads and attachments before drafting, proposes meeting times against your calendar, and sends you a daily brief. On the plans above Plus it manages several mailboxes at once.
Yuki reads the same inbox for a different purpose. The output is not a cleared inbox — it is a calendar with your flights already on it, a trip with the boarding passes attached, the subscriptions quietly renewing, and the parcel arriving Thursday. This page is written by the team behind Yuki, and it includes the ground where Jace is clearly ahead.
Say the awkward part first
Where Jace is ahead, specifically
- Rules and labels that act on their own. Jace classifies, routes and labels inside your actual mailbox, and keeps doing it once configured. Yuki classifies mail into its own list and leaves your mailbox untouched; the archive and label tools exist but run one approval at a time.
- Outlook and Microsoft 365, and more than one mailbox — two on Plus, eight on Pro. Yuki is one Gmail account.
- Real meeting scheduling. Jace reads the thread, checks calendars, works out the timezone and proposes times. Yuki can create an event and invite people, but nothing in it reads free/busy or proposes candidate times.
- Opt-in auto-send for routine replies. Yuki refuses this by construction, which is a choice rather than a gap — but if you want it, Jace has it.
- Attachments as drafting context. Jace reads PDFs and documents to write a reply. Yuki reads them into structured rows — a trip segment, a barcode, an invoice — which is useful for something else entirely.
What Yuki ships for email today, to everyone
- Extraction, on the free tier: flights, hotels and trains become trips with an itinerary; receipts and renewal notices become tracked expenses and subscriptions; shipping mail becomes a delivery you can watch; invites become calendar events.
- Focus emails (Pro): the mail that actually needs you, with newsletters, transactional noise and anything already turned into an event or expense filtered out.
- Read and answered are different things. A message leaves your list when you replied on that thread — not when you opened it.
- Reply suggestions (Pro): Yuki writes short options, and since September 2026 picking one shows you the full text and asks you to confirm before anything sends.
Side by side
| Yuki | Jace AI | |
|---|---|---|
| Entry paid price | €3.99/month | $25/month ($20 billed yearly) |
| Free tier | Free to download, 30-day Pro trial, no card | 7-day trial |
| Metered in credits | 10,000/month on Plus | |
| Gmail | ||
| Outlook / Microsoft 365 | ||
| More than one mailbox | 2 on Plus, 8 on Pro | |
| Drafts in your learned writing voice | Rolling out | |
| Rules and labels that act on their own | ||
| Proposes meeting times from your calendar | ||
| Can send routine replies without showing you each one | Refused by design | Opt-in |
| Shows the full text before anything sends | Unless auto-send is on | |
| Knows you already replied (read ≠ answered) | Not described | |
| Tracks what you are waiting on | Rolling out | Not described |
| Email becomes trips, expenses, subscriptions, deliveries | ||
| Native iOS and Android apps | Documented as not yet available | |
| EU data residency | ||
| Trains on your mail | ||
| Languages | 23 | English first |
The approval question, plainly
Jace's auto-send is its sharpest feature and the clearest difference between the two products. It can clear routine mail while you are asleep. Yuki cannot, and the refusal is enforced rather than promised: draft_email sits on a never-grantable list backed by a database constraint, so there is no permission a user could grant — or a future bug could invent — that would let a model send in your name without a card carrying the exact text. Every action Yuki takes is proposed, approved and then executed from the stored proposal, and the card is built from the server's own read of the thread rather than from the model's description of it.
That is a trade, not a victory. It means Yuki will always be slower at the inbox than a tool that is allowed to act alone. It also means there is no configuration in which Yuki sends something you have not read.
Where they are not really competing
Jace is not trying to build your trips, and Yuki is not trying to clear your inbox. A flight confirmation, to Jace, is a message to label; to Yuki it is a trip, a calendar entry, a boarding pass and a spend. Plenty of people could sensibly run both: Jace for the replies you owe at work, Yuki for the life admin underneath them.
Data, plainly
Jace's security documentation describes US infrastructure on AWS with standard contractual clauses for European customers, a subprocessor list that includes several model providers, and SOC 2 with a CASA Tier 3 assessment. Yuki keeps processing in the EU end to end, holds an independent CASA Tier 2 assessment from March 2026, and does not train on your data. Neither company claims to train models on customer mail.
Yuki's agent email features are rolling out behind a flag. What it organizes from your inbox works today — Yuki is free on iOS and Android.