Technology

Why Is My Thunderbird Not Receiving Emails From Outlook?

By Siddharth Thakur 13 Feb, 2026 78

It is frustrating to see that you have not received any mail for a long time as you may be waiting for an important reply. But then you find out that your Thunderbird stopped receiving emails. This problem can happen due to many reasons from a simple wrong password to a hidden setting that blocks your connection server.

The problem is that you cannot do any work whether it is personal or work-related without the use of your emails. Today we will look at why you are not getting emails and provide simple and clear steps to fix the connection. We will see how the manual and professional tools like the SysTools MBOX to PST Converter Tool help you to receive the emails and fix the connection.

Why Has Your Email Flow Stopped?

We have to see why your Thunderbird not receiving emails issue is happening before we understand the fixes. Imagine that Thunderbird is a telephone, for it to ring the wires should be connected, the power should be on and the other person must have the right number. The connection can break because of various reasons and these include:

  • Wrong Server Settings: The address that Thunderbird uses to find your mail has changed.

  • Password Issues: Security settings were updated by your email provider such as Outlook or Gmail.

  • Full Storage: Your computer has run out of space to hold new messages.

  • Security Blocks: Emails are taken as a threat by your antivirus or firewall.

Method 1: Check Your Server Settings to Fix Thunderbird Not Receiving Emails

The first place to look if your Thunderbird stopped receiving emails is the Account Settings. Many times when there is a small update on the provider’s end it can mean that the old settings no longer work. In such cases follow the steps mentioned below:

  1. Open the Thunderbird application and right-click on your email address in the sidebar.

  2. Select Settings and then go to the Server Settings.

  3. Check the Server Name in the Server settings.

  4. Make sure the Port number and Connection Security match with what your provider needs.

  5. Click on the Check for Messages button at the top to see if it starts a download.

Method 2: Fix Connection Issues with Outlook and Gmail

Many users get the issue of Thunderbird not receiving emails from Outlook or Gmail due to a feature called OAuth2. Use the following steps to use this feature:

  1. Locate the Authentication Method in your Server Settings.

  2. Try changing it to OAuth2 if it says Normal Password.

  3. A Google or Microsoft Windows will pop up when you try to get the mail.

  4. Log in to let Thunderbird see your mail. This simple change fixes the Thunderbird not getting emails error for modern accounts.

Method 3: Clear Your Storage and Compact Folders

Sometimes the inbox is full and this is the reason for Thunderbird not getting emails. The emails in Thunderbird are not deleted instead they are hidden, so you must compact the emails to make space for new ones. This is a common reason for not receiving emails if your inbox is over 4GB so look at these steps and learn how to compact the folders:

  1. Delete all the old, unwanted emails or large attachments.

  2. First right-click your Inbox folder.

  3. Then choose the Compact option.

  4. This will shrink the file size on your hard drive and allow the app to start receiving messages again.

The Automated Tool to Fix Thunderbird Not Receiving Emails

The problem may be in your local storage if you have checked your settings and your Thunderbird is not receiving emails. The application cannot write new emails into the files if your Thunderbird folders are corrupted or too large. When the manual methods fail then you can use the professional tool as it is designed to solve the problems in Thunderbird. You can use this software to access your data directly instead of struggling with broken data.

Why to Use This Tool?

  1. For each MBOX file the software creates a separate file by default.

  2. Wherever the Thunderbird emails are stored it can find them automatically.

  3. Exports MBOX files in various formats which the manual method does not provide: PST, MSG, EML, PDF, NSF, HTML, CSV.

  4. It creates a single PST file for multiple MBOX files.

  5. Can convert single or multiple profiles at once.

How to Use this Tool?

  1. Download and open the tool and then click on the Add File option.

  2. Click on the Select File(s)/Folder from File System option. Select Next and then the file and finally click Open.

  3. In the Mail section click on any mailbox folder to view its emails along with the attachments. You can also stop the process in between by clicking the Stop button.

  4. You can also change the view mode of the emails which is Horizontal view and Vertical view.

  5. The Preview mode allows you to see the file in multiple views such as Normal, Hex, Properties, Message Header, MIME, Email and HTML.

  6. Choose the Export button or select the right side Export button for bulk conversion.

Summary

Dealing with the Thunderbird not receiving emails situation can be stressful but most of the fixes are simple. We have seen that the problem starts with either a connection setting error or a full storage folder.

You should not forget to compact the folders to make space for the new ones if your settings are correct but you are still not getting emails. In case the application is too broken to fix you should use the automated tool as it is a safe way to protect your data and move it to a healthy mailbox. You can fix why your Thunderbird stopped receiving emails and get your inbox back to work by following these steps.