Comparison

Stamp Mail vs Upstream

Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.

Head to head
About

Stamp Mail

This AI-powered email client automates tasks like drafting replies, prioritizing messages, and extracting to-dos. It offers an agent to retrieve information and reorganize your inbox using plain English commands. A special mode allows quick review and approval of automated changes.

Highlights
  • Automated email drafting
  • Email prioritization
  • To-do extraction
  • Email summarization
  • Information retrieval via AI agent
  • Inbox reorganization
  • Approve/reject agent changes
Features
Read full description

Stamp is the AI Email Client that handles your emails for you. Stamp can automatically draft replies, prioritize important emails, extract todos, generate summaries, and more! With Stamp Agent, you can retrieve important information, reorganize your inbox, or perform any other action in plain English. What's more, with Stamp Mode you can quickly swipe through changes the agent made while you were gone, approving or rejecting them. Get started today, and experience what it's like to have your own AI personal secretary. Privacy Policy: https://www.stampmail.ai/privacy Terms of Use: https://www.stampmail.ai/tos

About

Upstream

This AI-powered inbox automatically organizes emails, drafts replies in your unique writing style, and sends follow-ups. It learns your workflow to minimize distractions and ensure no important messages are missed.

Highlights
  • AI email triaging
  • Personalized draft writing
  • Automated follow-ups
  • Self-organizing inbox
  • Learns user workflow
Features
Read full description

An AI inbox that triages itself, drafts in your voice, and follows up so you don’t have to remember to. ORGANIZE EMAILS YOUR WAY Upstream sorts, flags, and surfaces what needs your attention today. Noise gets filed away. No rules to set up or folders to maintain. It learns how you work and gets out of your way. DRAFTS IN YOUR VOICE. NOT A VOICE. Upstream writes like you. Not like AI pretending to be you. It studies how you write, how you talk to this specific person, and what the thread already sounds like, then drafts from there. The reply is waiting before you've finished reading the email. THE FOLLOW-UP WRITES ITSELF Upstream watches the threads going quiet, writes the nudge, and adds it to your inbox to send. The open loops close themselves. The ball never gets dropped.

Screenshots

Stamp Mail4 screens
Upstream4 screens

Verdict

The call

The clearest difference is rating: Stamp Mail at 5.0 against Upstream's 3.7. Upstream's advantage is in-app purchases (none vs 4). On price, ratings volume, update cadence and ads there is nothing between them.

Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS

CostPrice · In-app purchases · Ads · Monetization

Both are free to download. Stamp Mail sells 4 in-app purchases, starting at $20.00 per month. Upstream asks for nothing beyond the download.

ReceptionRating · Positive reviews · Number of ratings

Stamp Mail holds the better App Store score, 5.0 against 3.7. Both are backed by a comparable volume of ratings — 3 and 3 respectively.

UpkeepUpdate frequency

Stamp Mail ships an update weekly, Upstream every 2 weeks. The most recent releases landed on October 15, 2026 and October 2, 2026 respectively.

Scorecard3 real differences · 7 level
Stamp Mail versus Upstream: the parameters behind the verdict, then further details
ParameterStamp MailUpstream
PriceFreeFree
Rating5.0 (3 ratings) — better3.7 (3 ratings)
Positive reviews—50.0% of reviews
Number of ratings33
Update frequencyWeekly — betterEvery 2 weeks
AdsNoNo
In-app purchasesYesNo — better
MonetizationFreemiumFree — better
DevicesiPhone, iPad, iPod — betteriPhone, iPod
Requires iOS15.115.1
Further details — not scored
Size76 MB87 MB
Age rating4+4+
DeveloperStamp AIUpstream Labs

Customer experience

Stamp Mail

All ratings3 ratings
Positive100.0%
Neutral0.0%
Negative0.0%

Upstream

All ratings3 ratings
Positive66.7%
Neutral0.0%
Negative33.3%
Written reviews2 reviews
Positive50.0%
Neutral0.0%
Negative50.0%

In-app purchases

4 purchases

Stamp Mail

Subscriptions4
  • Stamp Individual (Monthly)7 Days trial$20.001 Month
  • Stamp Business (Monthly)7 Days trial$50.001 Month
  • Stamp Individual (Annual)7 Days trial$191.991 Year
Show 1 more
  • Stamp Business (Annual)7 Days trial$479.991 Year
None

Upstream

No in-app purchases

Questions

Is Stamp Mail free?
Stamp Mail is free to download, with in-app purchases available.
Is Upstream free?
Upstream is free to download, with no in-app purchases.
Which has better reviews, Stamp Mail or Upstream?
Stamp Mail is rated higher. Stamp Mail averages 5.0 out of 5 from 3 ratings, while Upstream averages 3.7 from 3 ratings.
Do Stamp Mail or Upstream have ads?
Neither Stamp Mail nor Upstream shows ads.
Which is updated more often, Stamp Mail or Upstream?
Stamp Mail ships an update weekly, and Upstream every 2 weeks. Most recently, Stamp Mail was updated on October 15, 2026 and Upstream on October 2, 2026.

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