Brandwave

How popular isMicrosoft Outlook?

In September 2026, people searched for Microsoft Outlook by name about 1.2 million times worldwide, a 33.3% decrease from the previous year. These searches made up 83.1% of all global email client searches, placing Microsoft Outlook first out of eight clients. When we asked both ChatGPT and Google AI Overviews about email clients, Microsoft Outlook appeared in all answers and was the most recommended of the eight.

Search and AI answers in September 2026

Microsoft Outlook is the most searched of 8 competitors and the most recommended in AI answers.

  1. Microsoft OutlookShare of searches 83.1%Mentioned in 5 of 5 AI answersPlace in AI recommendations 1st
  2. Apple MailShare of searches 9.2%Mentioned in 5 of 5 AI answersPlace in AI recommendations 2nd
  3. SparkShare of searches 2.8%Mentioned in 4 of 5 AI answersPlace in AI recommendations 4th
  4. ThunderbirdShare of searches 2%Mentioned in 4 of 5 AI answersPlace in AI recommendations 3rd
  5. SuperhumanShare of searches 1.8%Mentioned in 3 of 5 AI answersPlace in AI recommendations 6th

+3 more

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Top email clients in ChatGPT and Google AI Overviews

In three ChatGPT questions and two Google AI Overviews, Microsoft Outlook appeared in all five answers. Microsoft Outlook is the most recommended of the eight.

Most recommended by AI

Brands get a higher ranking if they are mentioned earlier in the answers.

  1. Microsoft Outlook1st
  2. Apple Mail2nd
  3. Thunderbird3rd
  4. Spark4th
  5. Proton Mail5th
  6. Superhuman6th
  7. Airmail–
  8. Newton–

Mentioned by AI

Each dot is one answer, filled in when that answer mentions the brand.

  • Microsoft Outlook5 of 5Named in 3 of 3 ChatGPT answersNamed in 2 of 2 Google answers
  • Apple Mail5 of 5Named in 3 of 3 ChatGPT answersNamed in 2 of 2 Google answers
  • Spark4 of 5Named in 2 of 3 ChatGPT answersNamed in 2 of 2 Google answers
  • Thunderbird4 of 5Named in 3 of 3 ChatGPT answersNamed in 1 of 2 Google answers
  • Superhuman3 of 5Named in 2 of 3 ChatGPT answersNamed in 1 of 2 Google answers
  • Proton Mail3 of 5Named in 2 of 3 ChatGPT answersNamed in 1 of 2 Google answers
  • Airmail0 of 5Named in 0 of 3 ChatGPT answersNamed in 0 of 2 Google answers
  • Newton0 of 5Named in 0 of 3 ChatGPT answersNamed in 0 of 2 Google answers

See every answer about email clients

5 answers

Not named in any answer:

Brands are shown in the order each answer named them. The survey took place in the United States on October 20, 2026.

Which email clients compete with Microsoft Outlook?

Microsoft Outlook against email clients worldwide, by month

Share of searches by month for Microsoft Outlook, Apple Mail, Spark. The figures are in the table below the chart.

View monthly share of searches table
MonthMicrosoft OutlookApple MailSparkThunderbirdSuperhumanAirmailNewtonProton Mail
Oct 202586.7%7.8%1.3%2%1.1%1.1%0.04%<0.01%
Nov 202584.8%9.3%1.3%2%1.5%1%0.06%<0.01%
Dec 202581.6%11%1.5%2.5%1.7%1.5%0.11%<0.01%
Jan 202684.1%9.2%1.2%2.6%1.8%1%0.06%<0.01%
Feb 202686.4%7.8%0.85%2.3%1.9%0.7%0.06%<0.01%
Mar 202685.7%7.7%1%2.4%2.3%0.85%0.05%0.01%
Apr 202684.4%7.6%1.3%2.9%2.7%1%0.11%0.01%
May 202684.9%7.7%1.3%2.6%2.7%0.85%0.05%0.01%
Jun 202685.1%7.7%1.5%2.1%2%1.3%0.25%0.01%
Jul 202683.5%9.2%1.5%2.6%2.1%1%0.08%0.02%
Aug 202683.8%9.3%1.5%2.4%1.6%1.3%0.05%0.02%
Sep 202683.1%9.2%2.8%2%1.8%1%0.05%0.02%

  1. 1.Microsoft Outlook

    83.1%

    Held 1st. 1.2M estimated branded searches, 0% vs prior month. Share -0.7 points.

  2. 2.Apple Mail

    9.2%

    Held 2nd. 135K estimated branded searches, 0% vs prior month. Share -0.1 points.

  3. 3.Spark

    2.8%

    Moved from 5th to 3rd. 40.5K estimated branded searches, +82.4% vs prior month. Share +1.2 points.

  4. 4.Thunderbird

    2%

    Moved from 3rd to 4th. 29.1K estimated branded searches, -18% vs prior month. Share -0.5 points.

  5. 5.Superhuman

    1.8%

    Moved from 4th to 5th. 27K estimated branded searches, +13.1% vs prior month. Share +0.2 points.

  6. 6.Airmail

    1%

    Held 6th. 14.9K estimated branded searches, -18.2% vs prior month. Share -0.2 points.

  7. 7.Newton

    0.05%

    Held 7th. 720 estimated branded searches, 0% vs prior month. Share 0 points.

  8. 8.Proton Mail

    0.02%

    Held 8th. 320 estimated branded searches, +23.1% vs prior month. Share 0 points.

Proton Mail sells other things too, so only its searches that name this product count here, like “email proton mail”.

Compare popularity between Microsoft Outlook and its closest rivals

Every comparison with Microsoft Outlook

7 comparisons

How has branded search demand for Microsoft Outlook changed worldwide over the last 12 months?

3 findings
  • Across the 12 months ending September 2026, estimated monthly branded searches for Microsoft Outlook worldwide fell from 1.8M to 1.2M.
  • Across the 12 months ending September 2026, Microsoft Outlook’s share of searches among email clients worldwide decreased from 86.7% to 83.1%.
  • Across the 12 months ending September 2026, Microsoft Outlook’s share of searches among email clients worldwide peaked at 86.7% in October 2025 and was lowest at 81.6% in December 2025.

How did search popularity change for email clients worldwide in September 2026?

6 changes

  1. In September 2026, Spark overtook Thunderbird and Superhuman to rank 3rd among email clients worldwide, with 2.8% of the searches.

  2. In September 2026, Microsoft Outlook lost share of searches among email clients worldwide, from 83.8% to 83.1%.

  3. Estimated monthly branded searches for Proton Mail worldwide rose 128.6% over 12 measured months, from 140 to 320 in September 2026.

  4. Estimated monthly branded searches for Superhuman worldwide rose 15.6% over 12 measured months, from 23.4K to 27K in September 2026.

  5. Estimated monthly branded searches for Airmail worldwide fell 33.2% over 12 measured months, from 22.3K to 14.9K in September 2026.

  6. Estimated monthly branded searches for Thunderbird worldwide fell 30% over 12 measured months, from 41.6K to 29.1K in September 2026.

How are Microsoft Outlook’s branded searches counted?

1 search term

Brandwave collects information about searches that people make online using Microsoft Outlook’s name. When viewed over time, estimated search volumes for this branded term can be used to understand whether interest in the brand is growing, holding steady, or fading.

  • microsoft outlook

How the Brand Demand Index is measured

Who owns Microsoft Outlook?

Microsoft Outlook is owned by Microsoft. Brandwave also tracks Microsoft Copilot, Azure AI Document Intelligence, Azure AI Search, Azure Bicep, Azure Blob Storage, Azure Container Apps, Azure Container Registry, Azure Cosmos DB, Azure Data Factory, Azure DevOps, Azure Machine Learning, Azure Pipelines, Azure Service Bus, Azure Stream Analytics, Bing, Clipchamp, GitHub Actions, GitHub Copilot, LinkedIn, LinkedIn Ads, LinkedIn Recruiter, LinkedIn Sales Navigator, Microsoft 365, Microsoft Advertising, Microsoft Authenticator, Microsoft Azure, Microsoft Bookings, Microsoft Clarity, Microsoft Defender for Cloud, Microsoft Defender for Office 365, Microsoft Defender Vulnerability Management, Microsoft Designer, Microsoft Dynamics 365, Microsoft Dynamics 365 Business Central, Microsoft Dynamics 365 Supply Chain Management, Microsoft Edge, Microsoft Entra, Microsoft Forms, Microsoft Learn, Microsoft OneNote, Microsoft Places, Microsoft Planner, Microsoft Power Automate Process Mining, Microsoft Power BI, Microsoft PowerPoint, Microsoft Purview, Microsoft Surface, Microsoft Teams, Microsoft To Do, Microsoft Translator, Microsoft Visio, Microsoft Whiteboard, Minecraft, OneDrive, OneNote, Outlook, Power Automate, SharePoint, Xbox and Xbox Game Pass, owned by the same company, worldwide.

Do you work for Microsoft Outlook? To request corrections or removal please contact us via our support page and we will be happy to assist.

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