Apparently, the IP which hosts the mailing lists I run has been added
to a spam blacklist by osirusoft (http://relays.osirusoft.com). I am not
an expert at these matters, but I'm told they are blocking a range of IP
numbers which happens to include this one (which is NOT a source of spam,
never has been and never will be). I'm also told that this IP uses qmail
which can return a false positive when tested for an open relay (which it
is not). It would appear that osirusoft does not base their blocking on
any FACTS that any spam has actually come from a given IP. As a result,
legitimate e-mail is being blocked by ISPs which use osirusoft for
I'm also told that it is very difficult to get off one of these
blacklists once you're on one.
Any suggestions other than moving the lists to a new host?