Through-the-web list creation and removal (with automatic
support depending on the MTA)
Multi-lingual support: list web pages and email notices can be in
any of nearly two dozen supported language, configurable
per-site, per-list, and per-user
"Real name" support for members
Much better password-less operation for simple user tasks.
Support for personalized deliveries and
VERP-like message
delivery for foolproof bounce detection
Emergency moderation
MIME-based content filtering, with demime/stripmime like options
Regular expression based topic filtering
Better membership management, including searching
Re-organized administrative requests pages
Moderated newsgroup support
A new architecture for the mail delivery subsystem, removing
the dependence on cron, for better responsiveness and
scalability
New moderation and privacy controls
Invitations
Autoresponse governors
Users can now change some of their delivery options globally,
for all lists at a site, including their password, delivery
status, real name, etc.
Much better MIME and I18n support in the archiver
A separate "list moderator" role has been added
Urgent: header support (bypasses digests to reach all users
immediately).
Web based list administration for nearly all tasks, including list
configuration, moderation (post approvals), management of user
accounts.
Web based subscribing and unsubscribing, and user configuration
management. Users can temporarily disable their accounts, select
digest modes, hide their email addresses from other members, etc.
A customizable home page for each mailing list.
Per-list privacy features, such as closed-subscriptions, private
archives, private membership rosters, and sender-based posting
rules.
Configurable (per-list and per-user) delivery mode