For all email client software we use, we configured it to use pop3. When I click on "Get Messages" in Thunderbird to get new email messages, I see Thunderbird status bar display something like "looked up....." followed by our domain name, and then nothing happened, and no error message displayed. Then, I though there is really no new email message in my mail account. Later, my colleagues, who use another email client, told me that their email client software displayed a connection error, and unable to receive email messages. Only after that, I know there is an issue with connection to our mail server (DNS issue), and then reported the issue to our email service provider. Unlike other email client software, Thunderbird does not alert me that there is an issue with connection to our mail server. Why is that? This is a very serious issue. If all of us use Thunderbird, we will be unaware of the connection issue. If we are unaware of the connection issue, we won't report the issue to our email service provider. If our customers send us an email, and we are unaware of the connection issue, and just thought that no new email message, it will affects our communication and relationship with our customers, and affects our business. How can I make Thunderbird display error message when there is connection issue to our mail server during the process of checking for new email messages on our mail server?