You’re Unable to Send or Receive Messages in Mozilla Thunderbird

Thunderbird might stop sending or receiving messages for several reasons. It could be an issue with the server settings, your antivirus program, or your internet service provider. Let’s check each case.

How to Fix

1. Check Account Settings

1. Click on the email account that experiences issues.
2. Under Options click on Account Settings.
3. Select Server Settings in the left-hand tab.

Make sure you’re using the 110 port, "None" connection security, and “Normal” password.

2. Check SMTP Settings

You need SMTP to send messages. To check SMTP settings:

1. Go to Account Settings like in the previous step.
2. Click “Outgoing server” in the left-hand tab.

Make sure you’re using the 587 port, “None” in connection security, and “Encrypted” password.

Now, you may able to send and receive messages.