AI assistant that writes email replies
Which AI assistant writes the best email replies for you?
Updated · 34 assistants ranked
This report ranks assistants on one job: replying to an email for you. Our test asks it to turn down a meeting time and offer two others, so it has to reply on the right thread, offer times that are really free, and sound like you. It is narrower than the inbox and calendar report, which also covers connected tools and a daily briefing; this one is only about the reply.
Top picks
- 110MuseTop pick
Email 10
- 210
Email 10
- 310
Email 10
- 49HarkBest free option
Email 9
- 59TownFastest that's still good
Email 9Time to finish 6m 30s
Top pick: highest average here. Best free option: highest among assistants you can use for free. Fastest that's still good: quickest median time to finish among those averaging 7 or more.
Full ranking
| # | Assistant | |
|---|---|---|
| 1 | Muse | 10 |
| 2 | Instinct | 10 |
| 3 | Dots | 10 |
| 4 | Hark | 9 |
| 5 | Town | 9 |
| 6 | Poke | 9 |
| 7 | Waldo | 9 |
| 8 | Asmi | 9 |
| 9 | Tomo | 8 |
| 10 | Norton Family Assistant | 8 |
| 11 | Familiar | 8 |
| 12 | Gemini Spark | 8 |
| 13 | Pally | 7 |
| 14 | szn | 7 |
| 15 | Ollie | 7 |
| 16 | Wajo / Fo | 7 |
| 17 | Caddy | 7 |
| 18 | Luke | 7 |
| 19 | Butler | 7 |
| 20 | Nessi | 7 |
| 21 | Neo | 6 |
| 22 | Alfi by Text.ai | 6 |
| 23 | Tressa | 5 |
| 24 | Persona | 5 |
| 25 | tinyNature | 5 |
| 26 | Joshu | 5 |
| 27 | Ask Ranger | 4 |
| 28 | Today | 4 |
| 29 | The Shadow | 4 |
| 30 | OpenClaw | 4 |
| 31 | Manus | 4 |
| 32 | OpenInstinct | 3 |
| 33 | AVA | 3 |
| 34 | Lucas | 3 |
How this report works
Assistants are ranked by their Email replies score. Only assistants that took the Email replies test are included, and a reply sent to the wrong person or at the wrong time counts against the score.
How to choose
- Decide whether it may send or only draft. Several assistants save a draft in Gmail for you to check, which is the safer start.
- Check the sign-off and tone on a real reply. The test compares the draft with your sent emails, so read one before you trust it.
- Look at the times it offers. A good reply checks your calendar; an assistant that guesses free slots will double-book you.
What users say
Last week it told me 'NOT TO OPEN' an email from a friend inviting me to a backyard BBQ—it turned out to be a phishing scam.
Open sourceSupposed to ping me when an email comes in and it doesn't for awhile.
Open sourceThe agent, which Meta launched on September 8, booked a Friday date night and made a packing schedule for my upcoming move. It also emailed a friend about a trip next month and made a planning document with places we want to visit.
Open sourceFirst, I asked it to look through my email and send me a daily digest of "important" emails (my inbox gets quickly clogged with PR pitches and newsletters). It did this admirably well.
Open sourceFrequently asked questions
Which assistant is best for this?
Muse leads with an average of 10.0, ahead of Instinct and Dots.
Is there a good free option?
Muse is the highest-ranked assistant with a free plan, averaging 10.0.
How did you test these assistants?
Every assistant got the same published tests, word for word, scored from three checkpoints and the number of corrections it needed. Each test is on the Dimensions page.