Fortunately, Mozilla Thunderbird includes support for simple mailing lists.
Create a Mailing List in Mozilla Thunderbird
Your Thunderbird address book can have more than one mailing list. You can add any contact with a valid email address to your mailing list.
Start Mozilla Thunderbird. Select Address Book in the toolbar at the top of the main window. Alternatively, you can access the Address book by selecting Tools > Address Book or using the keyboard shortcut Ctrl-Shift-B in Windows. Lifewire Select the New List icon on the toolbar or go to File > New > Mailing List. The New Mailing List dialog box opens. Lifewire Select the address book to which you want the new list to belong under All Address Books in the Add To drop-down list. If you only have one, select the name of the address book shown in the list. Lifewire Enter a name for the list in the Name field as well as a nickname in the List Nickname field and a brief description in the Description field, if desired. A description is especially helpful if you plan to make multiple similar mailing lists. Lifewire Begin adding email addresses to the mailing list. You can do so by typing them in by hand or copying and pasting them into the list. Addresses don’t need to be in your address book for you to add them to the list. When you begin typing, the autocomplete feature will suggest those that are in your address book to speed up the process. Thunderbird adds a new “skeleton” address card for those that did not exist in your address book. Select OK to save the mailing list and then close the dialog box for the list you just created. The list will appear in the Address Books pane under the associated address book.
Send a Message to Your List
Now that you have a list in your address book, mailing a group of people is easy.