Thunderbird Sending of Message Failed Timed Out



Thunderbird email client comes with various versions and is available for all major platforms. It is an open source client with support to POP, IMAP & SMTP.

There are situations when the user can’t send the email to the other end and will receive a message stating: “Thunderbird sending of message timed out”. The message could not be sent using SMTP server for an unknown reason.

This will create a problem for the user while sending the email.

What are the Possibilities of Thunderbird message failure error?

Message sending error in Thunderbird can be due to following reasons:

  • While updating Thunderbird and configuring the current account profile, the following error can come.
  • Antivirus update or Windows firewall blocked the sending of the emails by treating them as spyware or suspicious behaviour.
  • Wrong selection of SMTP port while configuring SMTP Server settings.
  • Connection Security is not set to SSL/TLS in the Server settings.
  • ISPs/providers have been restricting port 25 when they "detect" virus/spam mailings.

Solution to Thunderbird Sending of Message Failure

Perform the following Troubleshooting tricks for solving the issue:

  • Check whether Thunderbird is using the proxy for the connection through any Antivirus application.
  • Check the settings for SMTP Server and its assigned port.
  • Figure out whether the Antivirus or Windows firewall is blocking the Thunderbird working by disabling them.
  • Update the Thunderbird application to the latest version.
  • Download Wireshark tool to check the network traffic when Thunderbird is trying to send the outgoing message.
  • Try switching the Thunderbird SMTP Server configuration to secure/ssl, port 465 if port 587 doesn’t work.

Below is the sample setting configuration for Thunderbird

Secure SSL/TLS Settings (Recommended)
Username: Email address
Password: Use the email account’s password.
Incoming Server:
POP3 Port: 995
Outgoing Server:
SMTP Port: 465
Authentication is required for IMAP, POP3, and SMTP.

These are some of the tricks which can help the user to solve Thunderbird message sending failure issue.