How to Fix Outlook Error 0x800CCC0E (Send/Receive Failed)

Quick Fix

This error almost always means your outgoing (SMTP) server needs authentication enabled, or Outlook is using the wrong port/encryption. Try this first:

1. Open Account Settings. In Outlook, go to File > Account Settings > Account Settings, select your email account, and click Change.
2. Open More Settings. Click More Settings, then the Outgoing Server tab.
3. Enable authentication. Check the box for My outgoing server (SMTP) requires authentication, and select Use same settings as my incoming mail server.
4. Save and restart. Click OK > Next > Finish, then restart Outlook and try sending/receiving again.

Step-by-Step Guide

What this error means

Error 0x800CCC0E is a connection error in classic Outlook for Windows that appears during send/receive. It usually means Outlook cannot connect to the mail server. Although the interface shows "Connected," when actually sending or receiving emails, the connection between the client and the server fails, so the send/receive error keeps popping up. In many cases the root cause is specifically authentication: the error code refers to an authentication issue while using Outlook or during the setup of an account, mainly due to the server settings registered to the application. Other times it is caused by wrong port numbers, encryption mismatches, network problems, security software blocking the connection, or a corrupted Outlook profile/data file.

Fix 1: Enable outgoing server (SMTP) authentication

This is the single most common cause and fix for this exact error.

1. Open account settings. Go to File > Account Settings > Account Settings, select your account, click Change, then More Settings.
2. Go to the Outgoing Server tab. Click More Settings, then open the Outgoing Server tab, and tick the box labelled 'My outgoing server (SMTP) requires authentication.'
3. Match incoming settings. Select 'Use same settings as my incoming mail server,' or choose 'Log on using' and enter your username and password manually.
4. Save and test. Click OK, then Next, then Finish. Restart Outlook and try sending again.

Fix 2: Verify server names, ports, and encryption

1. Check account settings. Open Outlook and navigate to File → Account Settings → Account Settings. Select your email account and click Change. Ensure the following details are correct: your incoming mail server (IMAP or POP3), outgoing mail server (SMTP), server port numbers, and SSL or TLS encryption settings.
2. Use the right SMTP port. Most email providers require SMTP port 587 with encryption enabled (TLS or STARTTLS). If you are using SSL for SMTP, the port is usually 465.
3. Watch for IMAP/port mismatches. If the incoming or outgoing mail server address, port number, or encryption method is incorrect, Outlook cannot connect to the server — for example, using port 143 for an IMAP connection that requires SSL encryption will immediately reject the connection. If unsure of the correct values, confirm them with your email provider.

Fix 3: Check your internet connection

1. Test connectivity. Open a browser (for example, Microsoft Edge or Google Chrome) and browse to http://www.microsoft.com or http://www.bing.com. If these sites do not load, fix the PC's network first.
2. Force a sync. In Outlook, go to the View tab on the Ribbon, select the Sync button to force a send/receive, and watch the status bar at the bottom for sync progress or additional error details.
3. Restart networking hardware. If the connection is unstable, restart your router/modem and reconnect before retrying Outlook.

Fix 4: Temporarily disable firewall/antivirus email scanning

1. Test with security software off. Temporarily disable your firewall or antivirus software, then check if the error is resolved. If yes, make sure to add or allow Outlook as an exception in the security app.
2. Re-enable protection. Once confirmed, turn security software back on and add Outlook (and its ports, such as 587/465) as an exception instead of leaving protection off permanently.

Fix 5: Clear a stuck Outbox

1. Work offline. Under the Send/Receive tab choose Work Offline mode, then select the Outbox folder and move the stuck messages to the Draft folder or delete them.
2. Go back online and resend. Turn off Work Offline mode and try sending again.

Fix 6: Repair your profile or data file

1. Repair the account. Go to File > Account Settings > Account Settings, select your email account, and click Repair.
2. Run the Inbox Repair Tool. Classic Outlook often stores mail in a Personal Folders File (.pst) — run the Inbox Repair Tool (ScanPST) to repair the .pst file; this typically takes about 15 minutes.
3. Rebuild a damaged OST file. Close Outlook and rename the existing OST file — Outlook will create a new one on startup, as long as the mailbox is still active on the server.
4. Create a new profile as a last resort. Navigate to Control Panel > Mail > Show Profiles, then add and configure a new profile. This is platform-specific to Windows (Control Panel is not present on Mac or mobile Outlook).

When to seek further help

1. Contact your email provider/IT admin if server settings, ports, or authentication requirements are unclear, since server settings are usually determined by the administrator/host of your email account.
2. Use Microsoft Support and Recovery Assistant (SaRA) which can be opened to detect and fix Outlook issues automatically.
3. Escalate to data recovery specialists if the OST/PST file is severely corrupted and won't rebuild, or the mailbox itself is inaccessible on the server.