i was having serious rate-limiting localhost problems, causing messages to only send to portions of the list, timeouts, and other badness. i don't actually know the exact cause, but i'm 99% sure it was related to Lamson opening a new SMTP connection for every ... single ... message.
moved to mailman3, which is actually pretty spectacular with a nice REST api, and many other library-like qualities ... it's pretty much what Lamson *could* have been. if you have problems let me know; will be bringing other bits online over the next few days. thanks, -- C Anthony

