Create an Address Book Entry for Undisclosed Recipients

To make mailing undisclosed recipients easier, set up a special address book entry in Thunderbird for that purpose:

Select Address Book from the menu in Mozilla Thunderbird. Select New Contact. Type Undisclosed in the field next to First. Type Recipients in the field next to Last. Type your own email address in the field next to Email. Press OK.

Send an Email to Undisclosed Recipients in Thunderbird

To compose and send a message to undisclosed recipients in Mozilla Thunderbird:

Begin with a new message. Start typing “Undisclosed” in the To: field. Select Undisclosed Recipients from autocomplete drop down. Turn your attention to the BCC: field. Begin typing the first undisclosed. contact that you’d like to add, and select their info, should it pop up from the autocomplete drop down. Keep going, setting each new recipient field as BCC. BCC stands for blind carbon copy, meaning it’ll copy the message exactly but not allow your contacts to see who else received it. You can also use Mozilla Thunderbird address book groups to add multiple recipients in one go. When you’ve added all the undisclosed recipients you want in the BCC fields, write your message the way you normally would, and press Send.

The recipients will see Undisclosed Recipients in the area where they normally see other recipients’ names and email addresses thus preserving the privacy of all involved.