An attempt to categorize what the current mail setup does for Debian, and a wishlist for new features.
Standard alias file/role account handling
Different handling for different subdomains (e.g., the PTS has a header check that no other domain has, popcon is much more lenient about accepting mail with bad envelope senders, etc)
User settable per-user greylisting, RBL lookups, etc
User controlled forwarding, with different behavior depending on local_part_suffix (eg, email@example.com is handled differently than firstname.lastname@example.org)
Virtual domain support - per domain alias file/user/group/etc settings
bsmtp mail - should we keep this? Do people use it? It seems like this should be replaced by the more generic virtual domain handling.
Several anti-spam measures, but discussing the specifics here is probably not that useful.
$email@example.com forwards to the maintainer of the package and $package_contact@pts
- AUTH based relay?
- RSA sig based relay?
- mail hub/spoke architecture?
- Mail Admins Group
- weight RBL lists, and set cut-off level