Zackem vs New Outlook (2026)
We make Zackem, so read this knowing that. Every claim about Outlook links to Microsoft's own documentation or to independent reporting; where something is our opinion we say so.
The one-sentence difference
New Outlook is a Microsoft cloud service shown in a desktop window. Zackem is a program that runs on your computer. Almost every difference below comes from that.
What New Outlook does with mail that isn't Microsoft's
If you add a Gmail, Yahoo, iCloud or IMAP account to New Outlook, the app does not connect from your PC to that mailbox. It hands your sign-in to Microsoft, and Microsoft's servers fetch your mail, sync it into Microsoft's cloud, and show it to you from there. Microsoft documents this; independent coverage at Office Watch explains the mechanism in plain language. For many people that is fine. For anyone handling client mail, patient mail, or simply mail they would rather keep between themselves and their provider, it is the single most important fact about New Outlook, and it is rarely mentioned on the download page.
Zackem connects directly from your computer to each provider — Gmail, Microsoft 365, Outlook.com, Yahoo, iCloud, Zoho, any IMAP server. Your messages are stored on your own disk and nowhere else. We do not run a mail service and we never see your mail. The only thing that passes through our server is a request you make to Zackem AI, if you use it, and it is not stored.
Side by side
| New Outlook for Windows | Zackem | |
|---|---|---|
| Where Gmail / Yahoo / IMAP mail is processed | Microsoft's cloud, then your PC | Your PC only |
| Unlimited accounts | Yes | Yes, free |
| Local copy you own (PST-style archive) | No. New Outlook cannot save PST files and Microsoft says it will not (Office Watch) | Yes, full local store; uninstall takes it with you |
| Offline reading and search | Limited; the app keeps checking the online mailbox | Full, instant, offline |
| Each account kept separate, plus one combined view | Combined view | Both; duplicates shown once; replies go out from the account the mail came to |
| Classic add-ins, macros, profiles | Gone | Not applicable — AI side panel and integrations instead |
| AI help | Copilot with a Microsoft 365 subscription | Zackem AI paid by tokens, from $15 (20 free); or bring your own Claude, ChatGPT or Gemini |
| Price | Free with limits; Microsoft 365 from $19.99/yr to $99.99/yr | Free, unlimited accounts. You pay only for AI tokens and optional modules |
| Phone app | Yes | Not yet |
| Microsoft 365 / Exchange depth (shared mailboxes, delegation, Teams) | Native | Basic |
| Who makes it | Microsoft | Emaili LLC, an independent software company |
Where Outlook is better, honestly
If your office lives in Microsoft 365 — shared mailboxes, delegated calendars, Teams meetings from the calendar, retention policies — Outlook is the native client and Zackem is not trying to replace it there. Outlook also has a phone app on every platform today; Zackem does not have one yet. And Outlook has thirty years of trust; Zackem has a new company behind it and asks you to install it and decide for yourself.
Where Zackem is better
You have more than one mailbox and want them in one window without paying per seat. You want your mail on your own computer, not synced through a third party. You want a client that does not change on someone else's schedule — Microsoft began forcing commercial users off classic Outlook in April 2026 and supports existing installs "until at least 2029" (Office Watch, PCWorld). You want AI replies and summaries without a monthly subscription.
Switching
Install Zackem, add your accounts, and your mail downloads from each provider — nothing to export. Import from Outlook, Thunderbird and other clients is built in for local folders. Keep Outlook installed as long as you like; the two do not interfere.