Thunderbird outgoing server, also known as SMTP (Simple Mail Transfer Protocol), is responsible for sending emails from your Thunderbird client. Incorrect SMTP settings can cause emails to fail or remain stuck in the outbox. This comprehensive guide explains how to set up and troubleshoot the Thunderbird outgoing server for smooth email communication.

Why Configuring Outgoing Server Properly Matters

Without proper SMTP settings, your emails will not be sent, resulting in error messages like “Sending of the message failed.” Correct configuration ensures reliable delivery, maintains synchronization, and prevents account issues.

Step-by-Step Thunderbird Outgoing Server Setup

1. Open Thunderbird and go to Menu → Account Settings → Outgoing Server (SMTP).
2. Click Add or select an existing SMTP server to modify.
3. Enter the SMTP server name provided by your email provider (e.g., smtp.yourprovider.com).
4. Choose the correct port (587 with STARTTLS, or 465 with SSL/TLS).
5. Select authentication method: usually “Normal password” or OAuth2 for secure login.
6. Enter your email credentials if prompted.

Common Outgoing Server Settings

• SMTP Server: smtp.yourprovider.com
• Port: 587 (STARTTLS) or 465 (SSL/TLS)
• Authentication: Normal password / OAuth2
• Connection Security: SSL/TLS or STARTTLS

Troubleshooting Outgoing Server Issues

• Check username and password accuracy.
• Ensure correct server name and port number.
• Verify firewall or antivirus is not blocking Thunderbird.
• For Gmail/Office 365, use app passwords or OAuth2 authentication.
• Update Thunderbird to the latest version for better compatibility.

Best Practices for Thunderbird Outgoing Server

• Always use encrypted connections (SSL/TLS or STARTTLS).
• Use SMTP settings provided by your email service provider.
• Regularly test sending and receiving emails to ensure proper configuration.
• Backup Thunderbird profile regularly to prevent data loss.
• Enable two-factor authentication for enhanced email security.