The Thunderbird add-on WarnAttachment is an extension I developed to improve the security of handling email attachments. Since its release on May 1, 2017, it has protected users from the risks associated with potentially dangerous file attachments. Over 1,000 users now use the add-on daily. It's now available in eight languages, including German, English, French, Spanish, and many more, which makes me very happy.
The core function of WarnAttachment is to provide an extra layer of security. For file types considered unsafe, such as scripts or documents with macros, the add-on triggers a warning before the file is opened. This warning gives you the option to confirm or cancel the action, allowing you to make a conscious decision. Particularly risky formats, such as executable files (.exe), are completely blocked by default to protect you from accidentally running malware.
The add-on is customizable, so every user can configure the security levels to suit their needs. You can adjust the settings so that file types are either only warned about or blocked directly.
In an era where malicious email attachments are one of the most common attack strategies, WarnAttachment is a valuable tool for making your email communication more secure.