Outlook can show Cannot connect to server or stay on Trying to connect for several different reasons: internet trouble, service outages, password issues, offline mode, account settings, or a damaged local profile. Work through them from outside Outlook inward.
Does this affect you?
Use this for Outlook for Microsoft 365 and Outlook 2021 or 2019 on Windows or Mac with Microsoft 365, Exchange, IMAP, or POP accounts.
Rule out network and service problems
Check these before changing account settings.
- Open a browser and confirm websites load. If not, restart the router and fix the network first.
- Try wired Ethernet or a phone hotspot to rule out weak Wi-Fi.
- Check Microsoft 365 service health for Exchange or Outlook incidents.
- For work or school accounts, confirm whether VPN is required or whether the network blocks mail connections.
Fix Outlook settings and account issues
Use this after the internet and service status look normal.
- Re-enter the account password, especially if it changed recently.
- Run Outlook account repair from File > Account Settings > Account Settings > Repair.
- Check Send/Receive > Work Offline and turn it off if enabled.
- Use Microsoft Get Help or Outlook diagnostics for Microsoft 365 connection and password checks.
- For IMAP or POP accounts, confirm server names, ports, and security settings against the mail provider instructions.
More control
Create a new Outlook profile
On Windows, open Control Panel > Mail > Show Profiles, add a new profile, and set it as default. Outlook downloads the mailbox again and often clears stubborn profile corruption.
Check security software
A third-party firewall or antivirus can block Outlook. Test briefly with it disabled, then add an Outlook exception if that proves to be the cause.
Try classic versus new Outlook
If the new Outlook interface has connection trouble with an account, switch back to classic Outlook temporarily to compare behavior.
Use Cached Exchange Mode
For Exchange or Microsoft 365 accounts, Cached Exchange Mode keeps a local mailbox copy so short connection interruptions do not break Outlook as easily.
Sources
- Microsoft Support – Fix Outlook connection issues (2025)
- Microsoft Support – Outlook keeps asking for a password (2025)
- Microsoft 365 Status – Service health dashboard (2026)