Technology · head to head
Attio vs Microsoft Outlook
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
- -
The short version
- Each has a real cost: Attio the free plan stops at 3 seats and 50,000 records; 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: Attio covers Custom data model, 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 Attio and Microsoft Outlook actually diverge.
| Attribute | Attio | Microsoft Outlook |
|---|---|---|
| Platforms | Web, Ios, Android, Api | Web |
| Founded | 2021 | Unknown |
Identical on both: starting price (Free), pricing model (freemium), 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 Attio
- Custom data model
- Flexible views
- Email integration
- Calendar sync
- Automations
- Mobile app
- Real-time collaboration
- Templates
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.
Attio
- Sales pipelinenot Microsoft Outlook
- Customer managementnot Microsoft Outlook
- Deal trackingnot Microsoft Outlook
- Investor relationsnot Microsoft Outlook
- Partnership managementnot Microsoft Outlook
Microsoft Outlook
- Organisations on Exchange Online or Exchange Server where free/busy scheduling and room booking across everyone is a daily requirementnot Attio
- Executive assistants managing someone else's calendar and mailbox through delegate access, which no IMAP client supports properlynot Attio
- Regulated environments that need retention policies, legal hold and eDiscovery applied to mail centrally rather than per usernot Attio
- Teams handling shared inboxes such as support or accounts, where permissions and tracking matter more than the mail client itselfnot Attio
Where each one falls short
Documented limitations, not opinions. Every one is a constraint you would hit in normal use.
Attio
- The free plan stops at 3 seats and 50,000 records
- Outbound email is capped at 200 messages a month on the free plan and 1,000 on Plus
- Call Intelligence, sequences, advanced reporting and permission controls all require the Pro tier
- Custom objects are capped at 3 on free, 5 on Plus and 12 on Pro, with unlimited objects reserved for Enterprise
- File storage is capped at 50 GB on the free and Plus tiers
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
Attio
Free- FreeFree
- Up to 3 seats
- 50000 records
- 3 objects
- Plus$44/month
- Up to 10 seats
- 250000 records
- 5 objects
- Pro$99/month
- Unlimited seats
- 1000000 records
- 12 objects
- EnterpriseFree
- Custom pricing
- Unlimited objects
- Custom record limits
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 Attio if
- You need custom data model.
- You want to start without paying.
- You work on Web, Ios, Android, Api.
- You also want flexible views.
Choose Microsoft Outlook if
- You need exchange calendar integration.
- You want to start without paying.
- You also want delegate access.
Questions people ask
- Is Attio or Microsoft Outlook better?
- Neither clearly leads. Attio 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, Attio or Microsoft Outlook?
- Attio starts at Free and Microsoft Outlook at Free.
- Does Attio or Microsoft Outlook run on more platforms?
- Attio runs on Web, Ios, Android, Api. Microsoft Outlook runs on Web.
- Can I use Attio for free?
- Both have a free tier, so you can try either at no cost before committing.
- What is Attio best used for?
- Attio is most often used for sales pipeline, customer management, deal tracking, investor relations. Of those, sales pipeline and customer management are not what Microsoft Outlook is typically brought in for.
- What can Attio do that Microsoft Outlook cannot?
- Attio covers Custom data model, Flexible views, Email integration, Calendar sync. Microsoft Outlook covers Exchange calendar integration, Delegate access, Shared mailboxes, Rules and Quick Steps.
Answered from the vendors’ own pages
Attio: How much does Attio cost per user?
Attio's Plus plan is $44/user/month (or $35/month annually with 20% discount). Pro is $99/user/month (or $79/month annually). The Free plan includes up to 3 seats at no cost.
SourceMicrosoft 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.
Attio: What are Attio's seat and record limits for each plan?
Free plan includes up to 3 seats with 50,000 records. Plus supports up to 10 seats with 250,000 records. Pro offers unlimited seats with 1 million records. Enterprise has custom record limits.
SourceMicrosoft 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.
Attio: Are there additional costs for Attio beyond the per-user subscription?
Yes, workspace credits are available as add-ons ($70-$475/month depending on volume). Annual billing provides a 20% discount on the base per-user cost.
SourceMicrosoft 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.
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.
Related pages
More on Microsoft Outlook
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