Mailing lists in Bitmessage are used the same way mailing lists in a regular E-Mail system is used. members of a list write messages to it and the list server sends a copy of the message to everybody in the subscription list. In Bitmessage clients can send messages to a list without being a member. Additionally, clients can listen to the broadcast of the mailing list without ever sending to that list.
Become a member
For receiving messages from the mailing list, the user only needs to add an address to his Subscriptions. However, nobody is informed about this. To take part in a discussion the user simply writes a message to that address (revealing his own Bitmessage address to the Mailing List).
Create a list
To create a list, an address must be generated first. In the official PyBitmessage client, an address can be promoted to a Mailing list by right click on it and then change the special address behavior to "Behave as a preudo-mailing-list address". A name can be defined, this is used as prefix for broadcasts made by this mailing list, so if a client sends a message with the subject TEST to a list named YAY, it will look like this in response: [YAY] TEST.
A public list that includes mailing lists can be found in the forum.
An alternative are Decentralized Mailing Lists. They lack any form of protection against impersonation and spam but do not require a central address.