Gmail smtp error

"Unable to send mail through" is an error that occurs when there is a problem with sending emails through the SMTP (Simple Mail Transfer Protocol) server of Gmail. This issue can be caused by various factors, such as incorrect SMTP settings, authentication problems, firewall or antivirus restrictions, or Google account security settings.

Cannot send messages via Gmail SMTP

To solve the problem of being unable to send mail through, you can follow these troubleshooting steps:

  1. Check SMTP Settings: Ensure that you have correctly configured the SMTP settings in your email client or application. The SMTP server address should be set to, and the port number should be 587 (or 465 for SSL/TLS). Use your full Gmail email address as the username and enter the correct password.
  2. Enable "Less Secure Apps": If you are using a third-party email client or application, make sure to enable the "Allow less secure apps" option in your Google account settings. This allows the application to access your Gmail account for sending emails.
  3. Use App Password (Two-Factor Authentication): If you have enabled two-factor authentication for your Google account, you will need to generate an "App password" specifically for the email client or application you are using. This provides an extra layer of security for your account.
  4. Check Firewall and Antivirus: Some firewall or antivirus software may block outgoing email traffic. Temporarily disable any such programs and try sending the email again to see if they are causing the issue.
  5. Disable VPN: If you are using a Virtual Private Network (VPN), try disabling it temporarily, as it might interfere with the SMTP connection.
  6. Captcha Verification: In some cases, Google may require you to verify your account with a CAPTCHA test if they detect suspicious activity. Complete the CAPTCHA if prompted.
  7. Check Google Account Security Settings: Log in to your Google account and review the security settings. Look for any recent alerts or blocked sign-in attempts that might indicate unauthorized access.
  8. Clear Cache and Cookies: Clear your browser's cache and cookies, as they might sometimes cause conflicts with the SMTP connection.
  9. Contact Google Support: If none of the above solutions work, you can reach out to Google support for further assistance.


By following these steps, you can identify and resolve the issue preventing you from sending emails through and ensure that your email communication functions smoothly.