[Mailman-Users] 4.3.0 mail transport unavailable

[Stephen J. Turnbull]

Conrad G T Yoder writes:

 > I have recently (last couple weeks?) started getting "4.3.0 mail
 > transport unavailable” bounces from roadrunner/TW addresses (the
 > rate-limiting issue is not currently rearing its head), and that is
 > causing Mailman (2.1.17) subscriptions to be disabled.  Example
 > error message in the “Bounce action notification” email:

Note that the message you're reporting is a temporary failure (that's
what a 4.x.x status code means) so I don't really understand why the
bounce count is being incremented for this.  Whichever MTA is actually
talking to Time-Warner should be bumping this to a 5.x.x "permanent"
failure (in this case, giving up after trying repeatedly).