Here is how to add members to GNU Mailman's lists with a plain text file.
* "Mailman" in this post means not Mailman 3 but Mailman 2, because I use OpenBSD.
add_members command is the way.
Create a file to write members of a list in it. Its name is, for example,
firstname.lastname@example.org email@example.com firstname.lastname@example.org ...
$LIST_NAME (replace this with your list's name):
# /usr/local/lib/mailman/bin/add_members \ -r mailman-xxx.list $LIST_NAME \ # disable to send welcome messages to new members \ -w n
Then, your members are printed as registration success:
Subscribed: email@example.com Subscribed: firstname.lastname@example.org Subscribed: email@example.com ...