Microsoft Outlook
Dem still dey call am outlook, classic outlook, outlook.exe
Classic desktop mail and calendar from Office and Microsoft 365. The process na OUTLOOK.EXE. New Outlook na olk.exe. Windows Mail na HxOutlook.exe.
Wetin you need know
Classic Outlook na OUTLOOK.EXE. New Outlook and Windows Mail na other clients.
This article na about the Win32 Outlook where dey store profiles, OST/PST files, and COM add-ins. Microsoft 365 na the suite where dey often install am. The New Outlook toggle dey start different executable.
- Wetin e be?
- Classic desktop Outlook
- Same thing as New Outlook?
- No. That client na olk.exe
- Same thing as Windows Mail?
- No. Mail na HxOutlook.exe
Wetin be Microsoft Outlook?
Classic Microsoft Outlook na the desktop mail and calendar app where im image name na OUTLOOK.EXE. E be part of Microsoft 365 Apps or older Office. E no be New Outlook (olk.exe) and e no be Windows Mail (HxOutlook.exe).
If you never use am before
If your work mailbox don dey live inside Outlook for years, na classic desktop client usually be this: ribbon, profiles, and OST cache. E no be the Microsoft 365 suite page, e no be the New Outlook Store app, and e no be the Windows 10 Mail tile. Install am with Office or Microsoft 365. The "Try the new Outlook" switch dey leave this exe and start olk.exe.
Wetin dem dey use am for?
Exchange, Microsoft 365, and many IMAP accounts inside one Win32 window.
Offline cache and personal folders. New Outlook no dey treat PST the same way.
Classic Outlook dey load COM and VBA add-ins. olk.exe no dey host that model.
Na who e dey for?
- Work PCs where still need classic Outlook add-ins
- People where get PST archives where dem must continue to open
- Anybody where Windows 11 dey push toward New Outlook
Current status
Dey actively develop am, as Microsoft dey push plenty consumers go New Outlook. Classic Outlook still remain di Win32 client for Microsoft 365 Apps.
How old e be?
Outlook 97 launch for 1997 and replace Exchange Client and Schedule+ for plenty offices. E no be Windows Messaging from Windows 95, and e no be di 2022 New Outlook package.
Versions
Major channels first. Exact build numbers no dey all verified here.
System requirements
Values dey follow wetin di publisher release publicly. Workload still dey change di real need.
Minimum
| CPU | 1.6 GHz or faster, 2-core, per Microsoft for Microsoft 365 Apps |
|---|---|
| RAM | 4 GB for 64-bit, according to Microsoft. Large mailbox cache go need pass dat |
| Operating system | Current Windows release Microsoft list for Microsoft 365 Apps |
| Other | Some Outlook features need Microsoft Edge WebView2, according to Microsoft |
Resource profile
- CPU demand
- Indexing, add-ins, and huge inbox
- RAM demand
- Fit remain big after full workday of mail
- Disk demand
- OST growth under AppData
- Network demand
- Exchange / Microsoft 365 sync
Installed processes
Dese executables belong to dis product when e dey installed.
| OUTLOOK.EXE | Classic desktop Outlook |
|---|
Startup components
Classic Outlook fit start with Windows from im own option or shortcut. Dat one no be New Outlook and e no be di Mail app.
File locations
| Typical Click-to-Run | C:\Program Files\Microsoft Office\root\Office16\OUTLOOK.EXE |
|---|---|
| OST / PST | C:\Users\<you>\AppData\Local\Microsoft\Outlook\ |
File formats
Common wahala dem
Di New Outlook toggle dey hide dis client
Off "Try the new Outlook" if you still need PST or COM add-ins. olk.exe na different app.
Add-ins dey make Outlook show Not Responding
outlook.exe /safe na di classic add-in test. E no dey start New Outlook.
How to get unstuck
Check which Outlook you launch
Open file location. Office16\OUTLOOK.EXE na dis article. olk.exe na New Outlook. HxOutlook.exe na Windows Mail.
Start classic Outlook for Safe Mode
outlook.exe /safe dey skip COM add-ins. scanpst.exe na di inbox repair tool for dis client, no be for olk.exe.
Repair Microsoft 365 Apps if classic Outlook dey miss
No download outlook.exe from phishing zip. Work mail need di tenant admin if activation fail.
Alternatives
New Outlook, Outlook on the web, Thunderbird, and Windows Mail dey overlap to read mail. Dem no get di same PST and COM add-in tori.
Official help and downloads
Start with di vendor. Random exe sites no be support channel.
| Product page | www.microsoft.com/microsoft-365/outlook Wetin Microsoft dey release as Outlook |
|---|---|
| Outlook help | support.microsoft.com/outlook Help for profiles, sync, and crash |
| Classic vs new features | support.microsoft.com/office/feature-comparison-between-new-outlook-and-classic-outlook-de453583-1e76-48bf-975a-2e9cd2ee16dd Wetin you go lose if you switch |
| Command-line switches | support.microsoft.com/office/command-line-switches-for-microsoft-office-products-079164cd-4ef5-4178-b235-441737deb3a6 outlook.exe versus olk.exe |
| Requirements hub | www.microsoft.com/microsoft-365/microsoft-365-and-office-resources CPU, RAM, and OS Microsoft list |
Related hardware
Large OST go need SSD and enough RAM make classic Outlook no go dey page. GPU no dey speed up inbox sync.
Technical details
Technical details
Classic Outlook builds dey follow di Microsoft 365 channel. Dis article no pin any build.
Sources and verification
Recorded source label: August 2026. Dis label no establish independent verification. How we dey do research.
- Microsoft Outlook product page · Official Outlook product
- Microsoft Support: Outlook · Help for profiles, add-ins, and OST
- Feature comparison: new vs classic Outlook · Wetin each client fit do
- Foxhole process map · First-party samples on top Windows PCs. No be lab benchmark.
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