On Thu, 18 May 2000 19:42:11 -0400, Don Wiss <[log in to unmask]> wrote:
>Has your ISP implemented some new spam blocking and is now filtering out
>messages that have a null return path?
The quick test for this condition is send one message to LISTSERV@...
with the 2 line command:
command message: THANKS
INFO listname (name of your list)
You should get 2 separate responses back. The command acknowledgement and
response to THANKS is sent with RFC821 return-path MAIL FROM:<> which is
sometimes blocked (in violation of internet mail standards, see our FAQ at
http://www.lsoft.com/manuals/lsv-faq.stm#5.16)
The 'file under separate cover' (response to the INFO command) is sent with a
(non-blank) return-path of owner-listname@... and will not be blocked for being
blank. So if you get only one response (the second) you have strong indication
of blocking. If you get 2 responses consistently, then it is probably not a
blocking problem.