BCC Safeguard is a free Chrome extension designed to enhance privacy when sending emails through Gmail. It alerts users when the number of recipients in the 'To' and 'CC' fields exceeds a customizable limit, encouraging the use of the BCC field to prevent accidental exposure of contact information. This tool is particularly beneficial for those who frequently send mass emails and wish to maintain the confidentiality of their contacts.

The extension operates with a 'zero-footprint' approach, meaning it does not run background processes and only activates during email composition. Users can easily adjust the recipient threshold according to their preferences, with the default setting at five. Importantly, all counting occurs locally, ensuring that no email content or contact information is accessed or stored externally, thus prioritizing user privacy.