Thunderbird Common Problems and Their Solutions

There is always some kind of bug or error faced by users by routinely using the same application. It can create enormous difficulty that cannot be resolved by just restarting the utility or the systems. It often halts the working process and communication by restricting access to the mailbox in an email client. Such issues can be resolved by implementing simple manual procedures. This post covers all the Thunderbird common problems and their solutions. It discusses the most discussed or talked about topics in blogs and forums. It mentions the errors raised by users repeatedly on multiple occasions. Continue reading to find out more.

“I am part of an IT help desk team here in my company. I get regular complaints from employees about issues relating to Thunderbird email client. Often I am at a standstill and have to consult online blogs and forums. It would be great if I could get a summarized review. I can offer it as a pamphlet or email than repeating instructions each time.”

Mozilla Thunderbird Common Problems

Following are some of the most common issues mentioned by users worldwide:

Inability to Receive Emails

There can be some technical difficulty with the email client that may be causing this problem. It can be due to bad internet service, incorrect account configuration or ISP filters. Some Mozilla Thunderbird errors can be fixed by checking the account settings in the following manner:

  • First, launch the email client and go to Tools >> Account Settings >> Server Settings

  • Now, check the port number and other details. Match it with the ones mentioned on the account site.

Server Does Not Support Encryption

A warning may appear saying that the server does not support encryption. This makes communication vulnerable to hacking. Here are some steps to fix this issue:

  • In such a scenario, try clicking the Change Settings button and modify the settings

  • Or go ahead and check ‘I understand the risks’ and click the Create Account button and proceed
  • Also, one can try to change the email client that offers a secure connection.

Thunderbird Corrupt Trash Folder

There may be problems when deleting messages which can be fixed in the following manner:

  • First, launch the email client and go to Menu >> Help >> Troubleshooting information and click on ‘Open Folder’ button

  • Then, go to ‘ImapMail’ folder and select the appropriate IMAP account name
  • Next, delete the Trash and Trash.msf files

  • Finally, restart Thunderbird and automatically new trash files will be created.

Inability to Send Messages

This is one of the Thunderbird common problems encountered by many users. The reason for this is restricting SMTP access to current profile: This can be caused by:

  • Incorrect port number
  • Firewall/Antivirus program
  • Thunderbird in offline mode
  • Captcha set by some email providers
  • Incorrect outgoing mail settings

Thunderbird Crashes

It can be quite troublesome if this situation occurs in a workplace system. Some problems can be caused by Add-ins installed on the email client. It can also help to regularly update Thunderbird application. If all measures fail, try to report the issue to the Mozilla support. Get some help from their article and help forums. Report it on their site to get help from experts.


The Mozilla support is given if an individual faces similar issues but often it is not sufficient. These can get confusing at times and steps too tricky to be implemented by a non-technical user. It can be helpful to use this post as a guide to understanding the most Thunderbird common problems. It gives a brief overview of various such issues and their underlying cause. It goes out to mentions some manual steps that can be used to recover if such situations occur. Most of the steps are self-explanatory and easy enough to follow. This guide can be used by any professional, IT technician facing similar issues.