Outlook pinging noise on iMac and advice connection to the server failed or was dropped

Hi Jonathan Russell

I understand you’re having an issue with New Outlook for Mac (For home) showing “connection to the server failed or was dropped” along with an intermittent pinging noise on your iMac. I’m happy to help. What type of mailbox did you add in New Outlook for Mac (Outlook.com/Hotmail, Exchange/Microsoft 365, or third‑party IMAP/POP)? and whether it happens on all networks or only one?

Meanwhile, please try these steps:

1) Confirm Outlook is online and the Mac network is stable

Confirm your Mac has a working internet/network connection, and that Outlook isn’t set to work offline.

• In Outlook, open the Outlook menu and make sure Work Offline is not checked.
• Test your connection by opening a few websites in a browser.

2) If this is a POP/IMAP account: ensure SMTP authentication + verify account settings

Some POP/IMAP accounts require SMTP authentication, and incorrect credentials/settings can cause send/receive and connection issues.

• Go to Tools > Accounts > select the account.
• Under Outgoing server, click More Options, then select the correct authentication type and enter credentials if required.
• Also confirm the account email address, username, and password are correct under Tools > Accounts.

3) If a firewall/proxy/network is blocking mail server connections

Some networks/ISPs may block SMTP connections and that proxy requirements can prevent Outlook from connecting.

• If you suspect a network block, ask your ISP/network admin for an alternative SMTP server, then enter it under Tools > Accounts > Outgoing server.
• If your network requires a proxy, configure the mail proxy settings in macOS system settings (per your network admin’s guidance).

4) Check for known Outlook for Mac issues and update Outlook

Check list of known issues and workarounds for Outlook for Mac. Review it and ensure you’re on the latest build. See: Fixes or workarounds for recent issues in Outlook for Mac - Microsoft Support

Please tell me how it goes. If the problem persists, please don’t hesitate to reply to this thread and I will be happy to help. Have a lovely day!  

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The error and pinging noise indicate Outlook for Mac is repeatedly losing its connection to the mail server.

Use these steps to troubleshoot:

1. Confirm internet and Outlook online status
   • Verify the Mac is connected to the internet by opening a website in a browser.
   • In Outlook for Mac, on the Outlook menu, make sure Work Offline is not checked so Outlook is online.
2. Check for server or network issues
   • The message “connection to the server failed or was dropped” usually means the mail server or the network path to it is unstable.
   • If this worked previously and just started failing, contact the email provider or network administrator to confirm the mail server is online and not experiencing outages.
3. Verify account settings and authentication
   • In Outlook, go to Tools > Accounts.
   • Select the affected account in the left pane.
   • Confirm the email address, username, and password are correct.
   • For POP/IMAP accounts, under Outgoing server, click More Options and ensure the correct authentication type is selected and credentials are entered if required.
   • If the provider requires SSL or non‑default ports, confirm those settings with the provider and update them in the account configuration.
4. Check for firewall or proxy interference
   • Some ISPs or networks block connections to outgoing mail (SMTP) servers.
   • If another network (for example, home vs. office) works, the current network may be blocking the connection. Ask the ISP or network admin if an alternative SMTP server or port is needed.
   • If the network uses a proxy, configure it in macOS System Settings (System Preferences on older macOS) as specified by the network administrator so Outlook can reach the mail server.
5. Update Outlook for Mac
   • Open Outlook and select Help > Check For Updates.
   • Install any available updates and restart Outlook. Connection issues such as error 3253 (connection failed or dropped) can be resolved by updating.

If the pinging noise is tied to repeated error alerts, it should stop once the connection to the server is stable and Outlook is no longer repeatedly retrying and failing.

References:

• I can't send or receive messages with Outlook for Mac
• Outlook for Mac Help
• I can't send or receive messages in Outlook