Knowledgebase

Thunderbird: ‘Connection to server timed out’ error

In Thunderbird, you may receive a “connection to server timed out” error when sending or receiving a message. Connection timeout errors occur when the server takes too long to respond to a request from your device.

You may be able to prevent this error by increasing the length of time the email client will wait for a response from the server.

How to prevent timeout errors in Thunderbird

1. In Windows, open Thunderbird and go to Tools -> Options -> Advanced -> General -> Config Editor.

1. In Mac, go to Thunderbird -> Preferences -> Advanced -> General -> Config editor… Click to confirm “I accept the risk!”

2. In the search field, type in mailnews.tcptimeout.

3. Right click on that row and select Modify.

4. Change the value to a higher number, such as 1000 or 2000.

If you still receive a connection timeout error, there may be something else wrong with your internet connection, your computer, or our servers settings.

Troubleshooting SMTP Server Timeout in Thunderbird

1. ENSURE YOU HAVE THE MOST RECENT VERSION INSTALLED.

2. Choose Tools > Accounts… from the menu bar.

3. Click on “Outgoing Server (SMTP)”. You should see something like this…

If your User Name is not your full email address, or the Port, Secure Authentication or Connection Security Settings vary from those shown above, this may be the problem.

4. To change the User Name, Secure Authentication or Connection Security settings, click on ‘Edit’ and change them in there. Save the changes then restart Thunderbird before testing.

If you still are getting the error after changing, then you can change the Connection Security to “STARTTLS” in SMTP Settings. As many users have reported this is the only way they could get TB3 to work correctly.

Note: Always remember to save the new settings and restart Thunderbird before testing again.