The Mail | Announcement lists function does not say if it is really a third-party app, such as PHPlist http://tincan.co.uk/?lid=294&cc=1 It would be helpful to know if it is so we can go to the source site for documentation and support. If not, some of us might want to install PHPlist ourselves. It would be helpful if that were a one-click option.
If you go to MAIL >> Overview >> Discussion Lists, it explains that the app is Mailman. Here is a link to the site:
The DH discussion lists run Mailman, but their announcement lists apparently do not. The difference is that Mailman is primarily for discussion lists (hence the name) where any subscriber can post to the list. You can use it for announcement lists with no public posting as well, but it’s not very elegant (not that Mailman is very elegant to begin with), which is likely why the DH announcement list uses a different system.