Hristo Venev via Mailman-users writes:
How do I configure mailman to use a unix socket for lmtp connections?
I don't think it's currently possible. Using a Unix socket is undocumented in Mailman. Mailman's LMTP server is based on aiosmtpd, which as far as I can tell from its documentation does not support Unix sockets.
Setting
[mta] incoming: mailman.mta.null.NullMTA lmtp_host: /path/to/socket
That's the smtpd package's style of configuration, but I don't think it works with aiosmtpd.
The underlying asyncio package does support Unix sockets, so it's *probably* not too hard to add this feature *in principle*. However, if aiosmtpd doesn't support it, somebody (preferably not us) will have to fork and go through the feature submission process, and maintain it separately for quite some time since we support fairly old Python versions. And async code is fundamentally hairy, if we have to get into any details (*probably* not, but speaking for myself I'm not going to dig into something without a reserve of time on "probably").
Also, I don't think we have any experts in this code at this time, and I'm not going to have enough time to work on it for a month, at least, and more likely around the new year. Maybe somebody else does, but I know some of our developers will be out of touch for a while. You could try the aiosmtpd package maintainer, or the upstream Python channels (python-list@python.org).
Steve