AIRANKS — The Authoritative Rankings for AI Web Content

AIRANKS measures AI visibility: we ask AI models real product and service questions, capture the complete answers as immutable observations, and publish what they contain — which brands were mentioned, which domains were cited, and which exact pages were linked. Every domain gets an AIR score from 1–10 (a decile of visibility in the active dataset; 0 means insufficient data), with the methodology in the open.

AIR

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The Question

← all rankings / dataset COBALT

What is the best email client

Outlook takes the top spot in 77.2% of resamples. Of 13 ranked brands, only 4 hold a position we'd call firm.

0
answers sampled
0
brands named
1,000
bootstrap resamples

Who AI Cites For This Question

25 cited pages · bars vs the leader

I ditched Apple Mail for this game-changing app - and I'm not going backwww.tomsguide.comtomsguide.com/computing/software/i…ck?utm=airanks.net90
Thunderbird — Free Your Inbox. — Thunderbirdwww.thunderbird.netthunderbird.net/en-US/features/?utm=airanks.net85
Gmail: Secure, AI-Powered Email for Everyone | Google Workspaceworkspace.google.comworkspace.google.com/intl/en/gmail/?utm=airanks.net83
Thunderbird FAQ | Thunderbird Helpsupport.mozilla.orgsupport.mozilla.org/en-US/kb/thund…aq?utm=airanks.net78
What is Outlook? | Microsoft Supportsupport.microsoft.comsupport.microsoft.com/en-us/outloo…ok?utm=airanks.net73
The 9 Best Email Apps in 2026 | Zapierzapier.comzapier.com/blog/best-email-app/?utm=airanks.net70
Get started with Thunderbird | Thunderbird Helpsupport.mozilla.orgsupport.mozilla.org/en-US/kb/getti…rd?utm=airanks.net61
Feature comparison between new Outlook and classic Outlook | Microsoft Supportsupport.microsoft.comsupport.microsoft.com/en-US/Outloo…ok?utm=airanks.net44
Learn about Gemini features in Gmail - Gmail Helpsupport.google.comsupport.google.com/mail/answer/16831098?utm=airanks.net43
‎Mail App - App Storeapps.apple.comapps.apple.com/us/app/mail/id1108187098?utm=airanks.net42

The Ranking, With Its Uncertainty

Outlook soft Outlook — ci 0.92–1.00 · n=369 · 77.2% of resamples held this rank · named in 77% of answers
Gmail soft Gmail — ci 0.92–1.00 · n=369 · 77.2% of resamples held this rank · named in 77% of answers
Proton Mail firm Proton Mail — ci 0.75–0.83 · n=369 · 87.9% of resamples held this rank · named in 63% of answers
iCloud Mail firm iCloud Mail — ci 0.75–0.83 · n=369 · 87.7% of resamples held this rank · named in 76% of answers
Thunderbird locked Thunderbird — ci 0.67–0.67 · n=369 · 98.9% of resamples held this rank · named in 76% of answers
Spark locked Spark — ci 0.58–0.58 · n=369 · 100.0% of resamples held this rank · named in 36% of answers
Mimestream soft Mimestream — ci 0.42–0.50 · n=369 · 69.4% of resamples held this rank · named in 21% of answers
Yahoo Mail soft Yahoo Mail — ci 0.42–0.50 · n=369 · 69.1% of resamples held this rank · named in 15% of answers
Superhuman soft Superhuman — ci 0.25–0.33 · n=369 · 71.7% of resamples held this rank · named in 11% of answers
Fastmail soft Fastmail — ci 0.25–0.33 · n=369 · 71.3% of resamples held this rank · named in 5% of answers
eM Client contested eM Client — ci 0.08–0.17 · n=369 · 53.6% of resamples held this rank · named in 2% of answers
Shortwave contested Shortwave — ci 0.08–0.17 · n=369 · 53.9% of resamples held this rank · named in 2% of answers
Tuta gathering Tuta — gathering data, n=369. No bootstrap interval yet.

The Incomparability Lattice

what the intervals separate, not what the list claims

An edge means one brand's interval sits strictly above another's — zero overlap. No edge between two brands is not a gap in the drawing, it is the finding: their intervals overlap, and the bootstrap cannot tell them apart. Brands on the same rung are incomparable, not tied — the ranking above orders them anyway because a list has to print a total order; this diagram is the honest version.

Outlook

0.92–1.00

Gmail

0.92–1.00

Proton Mail

0.75–0.83

iCloud Mail

0.75–0.83

Thunderbird

0.67–0.67

Spark

0.58–0.58

Mimestream

0.42–0.50

Yahoo Mail

0.42–0.50

Superhuman

0.25–0.33

Fastmail

0.25–0.33

eM Client

0.08–0.17

Shortwave

0.08–0.17

12 of 13 brands measured · 17 dominance edges · 7 rungs · 5 pairs the data does not separate