How to Fix Mozilla Thunderbird Not Connecting to Server Issue?

Mozilla Thunderbird is a popular and reliable email client used by millions worldwide. It provides users with a seamless experience for managing their emails, contacts, calendars, and more. However, like any other software Thunderbird may also encounter issues like not connecting to the server. This problem can be frustrating and adversely affect the overall productivity.

That is also the prominent cause of Thunderbird to Outlook migration. Since; there are a plethora of alternatives available to Thunderbird, any bug; which you cannot rectify; leads to email migration. Thus, to avoid such circumstances, in this blog post, we will explore some common causes behind this issue and provide step-by-step solutions to help you get Thunderbird back up and running smoothly.

How to Fix Thunderbird Server Connection Issue?

The server connectivity issue is important to address; because that will not let you send/receive emails. Here is the list of primary causes of this issue and how you can rectify it without hampering the data.

Check Your Internet Connection

Before diving into Thunderbird’s settings and configurations, the first thing you should check is, your internet connection. Ensure your device is connected to the internet and try accessing other websites or applications to confirm its stability. If there are connectivity issues, resolve them before proceeding further.

Verify Server Settings

In Thunderbird, incorrect server settings can prevent the application from connecting to your email provider. Follow these steps to verify your server settings:

Step 1: Open Thunderbird and navigate to “Tools” in the menu bar. Step 2: Select “Account Settings” from the drop-down menu. Step 3: In the left pane, select the account; that is causing the issue. Step 4: Review the “Server Settings” section to ensure the incoming and outgoing server names, port numbers, and security settings are accurate.

Check Firewall and Antivirus Settings

Sometimes, security software like firewalls or antivirus programs may interfere with Thunderbird’s connection to the server. To rule out this possibility, temporarily disable your firewall and antivirus software and check if Thunderbird can connect to the server. If the issue resolves, adjust the settings in your security software to allow Thunderbird to access the internet.

Investigate Email Provider’s Status

At times, email servers might experience temporary outages or maintenance, which could lead to Thunderbird not connecting. Visit your email provider’s website or social media channels to check for any service announcements or reports of server issues. If there’s a problem with their servers, you’ll need to wait until it’s resolved on their end.

Update Thunderbird to the Latest Version

Outdated software can lead to compatibility issues, including problems with server connections. Ensure you use the latest version of Thunderbird. To check for updates, follow these steps:

Step 1: Open Thunderbird and go to the “Help” menu. Step 2: Select “About Thunderbird” from the drop-down list. Step 3: Thunderbird will automatically check for updates and prompt you to install any available updates.

Disable Add-ons and Extensions

Third-party add-ons and extensions in Thunderbird can sometimes interfere with the application’s functionality. Try to disable all add-ons and extensions and restart Thunderbird to see if the problem persists. If Thunderbird connects successfully, one of the add-ons could be causing the issue. After that, enable them one by one to find the wrongdoer.

After figuring out these methods, if you are still facing the “Mozilla Thunderbird Not Connecting to Server error”, it is high time to either reset Thunderbird; or export Thunderbird data to Outlook to read Thunderbird emails in MS Outlook. Since MS Outlook is the most sought-after application for emailing, it is more likely; that users prefer it over Thunderbird; whenever there is an unresolvable glitch. Also, like Outlook, Thunderbird does not provide any inbuilt repair tool to overcome any error; one needs to start from scratch or consider data migration. 


Experiencing issues with Mozilla Thunderbird not connecting to the server can be frustrating; but with a methodical approach, you can resolve the problem and get back to managing your emails efficiently. Remember that email server connections can be influenced by various factors. Thus, don’t hesitate to reach out to your email provider’s support, if the problem persists. Armed with these troubleshooting tips, you’ll be better equipped to tackle Thunderbird connectivity issues and enjoy a seamless email experience once again.

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