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Auth0 vs Microsoft Outlook

Auth0 logo

Auth0

Technology

Secure access for everyone

From
Free
Rated
-
Full reviewWebsite
Microsoft Outlook logo

Microsoft Outlook

Technology

Microsoft's email and calendar client, in the middle of a transition from the classic Windows application to a web-based replacement.

From
Free
Rated
-
Full reviewWebsite

The short version

  • Each has a real cost: Auth0 free tier limited to 25,000 monthly active users, requiring upgrade for growth beyond that; Microsoft Outlook microsoft is replacing the classic Win32 client with the new web-based Outlook, and the new one runs only web add-ins, not COM add-ins, so any line-of-business integration for CRM, dictation, document management or telephony must be rewritten or the desktop stays on classic until its support window closes.
  • They diverge on capability: Auth0 covers Universal login, Microsoft Outlook covers Exchange calendar integration.
  • Prices and features above were last checked on 30 August 2026.

Where they differ

Only the attributes on which Auth0 and Microsoft Outlook actually diverge.

Attributes where Auth0 and Microsoft Outlook differ
AttributeAuth0Microsoft Outlook
Pricing modelUnknownfreemium
PlatformsWeb, iOS, AndroidWeb
Founded2013Unknown

Identical on both: starting price (Free), free tier (Yes), user rating (Not yet rated), category (Technology).

What each one covers

Drawn from each product's published feature list. An absence here means we hold no record of it - not that the product lacks it.

Only in Auth0

  • Universal login
  • Social login
  • Multi-factor authentication
  • Passwordless
  • User management
  • Anomaly detection
  • Extensibility
  • Machine to machine

Only in Microsoft Outlook

  • Exchange calendar integration
  • Delegate access
  • Shared mailboxes
  • Rules and Quick Steps
  • Retention, hold and eDiscovery
  • Sensitivity labels and encryption
  • Add-in platform
  • Offline cached mode

What people use each for

The jobs each tool is most often brought in to do.

Auth0

  • B2C authenticationnot Microsoft Outlook
  • B2B authenticationnot Microsoft Outlook
  • B2E authenticationnot Microsoft Outlook
  • API securitynot Microsoft Outlook
  • Mobile app securitynot Microsoft Outlook

Microsoft Outlook

  • Organisations on Exchange Online or Exchange Server where free/busy scheduling and room booking across everyone is a daily requirementnot Auth0
  • Executive assistants managing someone else's calendar and mailbox through delegate access, which no IMAP client supports properlynot Auth0
  • Regulated environments that need retention policies, legal hold and eDiscovery applied to mail centrally rather than per usernot Auth0
  • Teams handling shared inboxes such as support or accounts, where permissions and tracking matter more than the mail client itselfnot Auth0

Where each one falls short

Documented limitations, not opinions. Every one is a constraint you would hit in normal use.

Auth0

  • Free tier limited to 25,000 monthly active users, requiring upgrade for growth beyond that
  • Advanced features like MFA and RBAC only available on paid Essentials tier and above
  • Ownership by Okta introduces risk that independent product roadmap may change

Microsoft Outlook

  • Microsoft is replacing the classic Win32 client with the new web-based Outlook, and the new one runs only web add-ins, not COM add-ins, so any line-of-business integration for CRM, dictation, document management or telephony must be rewritten or the desktop stays on classic until its support window closes.
  • The new client's handling of non-Microsoft accounts synchronises mail through Microsoft's cloud rather than connecting from the machine to the provider, which several organisations' data residency and handling policies do not allow, and it is not an optional behaviour.
  • PST and OST files are a single-file, corruptible and effectively unshareable store, and the new client's reduced PST support means years of personal archives sitting in those files need an explicit migration plan rather than carrying forward.
  • Large mailboxes turn software problems into administration ones: search index rebuilds, OST files of tens of gigabytes and the mailbox quotas of whichever plan was bought, and the usual fix is archiving policy rather than anything a user can do.
  • Against IMAP or Gmail you lose most of what justifies it, including free/busy lookup, room booking, delegate access, and retention and compliance policies, because those are Exchange server features rather than client features.
  • The five or six products sharing the Outlook name have materially different feature sets, so internal documentation, training and support procedures must be written per platform and a user moving between desktop, web and mobile finds the same task done differently in each.

Pricing, plan by plan

Auth0

Free
  • FreeFree
    • Up to 25,000 monthly active users
    • Basic authentication
    • Email/password login
  • Essentials (B2C)$35/month
    • Unlimited MAUs beyond free tier
    • Multi-Factor Authentication
    • Role-Based Access Control
  • Professional (B2C)$240/month
    • All Essentials features
    • Advanced security
    • Custom branding

Microsoft Outlook

Free
  • Outlook (Free)Free
    • 15 GB mailbox storage
    • 5 GB cloud storage
    • Web and mobile Office app access
  • Microsoft 365 Basic$1.99/month
    • 100 GB mailbox storage
    • 100 GB cloud storage
    • Ad-free experience
  • Microsoft 365 Personal$9.99/month
    • 1 TB cloud storage
    • Desktop Office apps (Word, Excel, PowerPoint, Outlook, OneNote)
    • Copilot with high usage limits
  • Microsoft 365 Family$12.99/month
    • 1-6 users
    • Up to 6 TB total cloud storage (1 TB per person)
    • Same apps and features as Personal

Which should you pick?

Choose Auth0 if

  • You need universal login.
  • You want to start without paying.
  • You work on Web, iOS, Android.
  • You also want social login.
Auth0 review

Choose Microsoft Outlook if

  • You need exchange calendar integration.
  • You want to start without paying.
  • You also want delegate access.
Microsoft Outlook review

Questions people ask

Is Auth0 or Microsoft Outlook better?
Neither clearly leads. Auth0 starts at Free and Microsoft Outlook at Free, and user ratings are close enough to be indistinguishable. Choose on capability and platform support.
Which is cheaper, Auth0 or Microsoft Outlook?
Auth0 starts at Free and Microsoft Outlook at Free.
Does Auth0 or Microsoft Outlook run on more platforms?
Auth0 runs on Web, iOS, Android. Microsoft Outlook runs on Web.
Can I use Auth0 for free?
Both have a free tier, so you can try either at no cost before committing.
What is Auth0 best used for?
Auth0 is most often used for b2c authentication, b2b authentication, b2e authentication, api security. Of those, b2c authentication and b2b authentication are not what Microsoft Outlook is typically brought in for.
What can Auth0 do that Microsoft Outlook cannot?
Auth0 covers Universal login, Social login, Multi-factor authentication, Passwordless. Microsoft Outlook covers Exchange calendar integration, Delegate access, Shared mailboxes, Rules and Quick Steps.

Answered from the vendors’ own pages

Auth0: How much does Auth0 cost?

Auth0 has a Free tier for up to 25,000 monthly active users (MAUs). Paid plans start at $35/month (Essentials B2C) and scale to $240/month (Professional B2C) and higher for Enterprise. Pricing scales with MAU usage.

Source
Microsoft Outlook: What is the difference between classic Outlook and the new Outlook for Windows?

Classic is the long-standing Win32 application shipped with Microsoft 365 and Office LTSC. The new Outlook is a web-based client that replaced Windows Mail and Calendar. The most consequential difference is add-ins: the new client supports only web add-ins, not COM add-ins.

Auth0: Does Auth0 include Multi-Factor Authentication?

No. MFA, RBAC (Role-Based Access Control), and premium support are not included in the free tier and require upgrading to paid Essentials plans or higher.

Source
Microsoft Outlook: How long will classic Outlook be supported?

Microsoft has stated support through at least 2029. That is a planning window rather than a reprieve, and organisations with COM add-in dependencies should be scoping the replacement work now.

Auth0: Is Auth0 independent or part of a larger company?

Auth0 was acquired by Okta in May 2021 for $6.5 billion. It now operates as a subsidiary business unit within Okta, but maintains its own brand and operations.

Source
Microsoft Outlook: Can I use Outlook with Gmail or another IMAP provider?

Yes, but with reduced capability. You lose free/busy lookup, room booking, delegate access and server-side compliance policies, because those come from Exchange rather than from the client.

Auth0: Who should use Auth0 vs Okta?

Auth0 is developer-focused and serves customer identity use cases (B2C). Okta serves workforce identity (B2B) and has broader enterprise features. Auth0 now serves both markets post-acquisition but maintains its developer-friendly positioning.

Source
Microsoft Outlook: Is Outlook free?

Outlook on the web and the mobile apps are free with a Microsoft account, and the new Outlook for Windows is included with Windows 11. The classic desktop application requires a Microsoft 365 subscription or an Office perpetual licence.

Microsoft Outlook: Will my COM add-ins work in the new Outlook?

No. The new client supports only the cross-platform web add-in model. Vendors must publish a web add-in, and where they have not, the choice is to stay on classic Outlook or replace the integration.

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