Javad Hoseini-Nopendar writes:

I have created a mailing list named IranRAVI@IranRAVI.com, but I have a problem. I believe a few members of the mailing list don't really like to receive all the emails of the list. They don't like to take part in discussions. but they only like to receive the newsletters. Now I want to create a Topic or a sub-mailing list. For example: IranRAVI-Newsletter@IranRAVI.com

This requirement is quite simple: just add IranRAVI@IranRAVI.com as a subscriber to IranRAVI-Newsletter@IranRAVI.com. Tell users to subscribe to only one of the two lists, or they will receive duplicates.

This way, when I send an email to IranRAVI-Newsletter@IranRAVI.com, the subscribers of this list will only receive the newsletter, but can't reply to group. They can only reply to the sender.

You cannot do exactly what you say with Mailman. The "Reply-To" function is part of the mail client the subscriber uses, and Mailman cannot prevent them from sending mail to any address they like.

At the same time, the subscribers of IranRAVI@IranRAVI.com will also receive this email. The subscribers of IranRAVI@IranRAVI.com should be able to take part in the discussions by replying to the group.

What you can do is

• Set IranRAVI-Newsletter to refuse member posts.
• Set IranRAVI-Newsletter to accept posts from you (and other authorized posters' addresses, if any).
• Set IranRAVI-Newsletter to DISCARD (not REJECT!) posts from anyone else.
• Set IranRAVI-Newsletter's reply-to to the appropriate address (which can be the same as the authorized posting address, but doesn't need to be).

All of the above is perfectly safe, since the Newsletter is intended to be read-only, and its subscribers want that. Then

• Set IranRAVI's reply-to to the list, OR

This can create problems depending on the nature of the list. If a subscriber decides to send a nasty message to another one, *both* reply to list and reply to author send to the *list*. This almost forces them to hold their fight in public, which you probably don't want.

• Set IranRAVI's reply-to to remove existing reply-to, OR

This can also create problems if any of your users are sophisticated enough to use Reply-To themselves, but you need to remove the Reply-To set by IranRAVI-Newsletter (which is sending posts to IranRAVI).

• Add a Handler to the mail processing pipeline to remove the IranRAVI-Newsletter Reply-To from posts to IranRAVI.

This is safe but you need to be able and willing to add code to your Mailman installation, and add a configuration option to IranRAVI using the command-line tool (it's not possible from the web interface). This is also fairly safe because it will only affect IranRAVI, and it's easy to test and fix. If you are interested in this option, let us know and we can explain the procedure.