Quoting Michael Paoli (Michael.Paoli@cal.berkeley.edu):
And ... perhaps that was false positive ... if I drop out the header: From: <> and don't even give a From: header at all, those same quite minimal email tests make it through just fine. I did notice sometimes there's substantial delay (maybe up to about 10 seconds or so) after: RCPT TO:postmaster@balug.org and before it responds with: 250 Accepted ... but even in "worst case", that probably ought only cause some temp failure if client times out on that?
Yes, I noticed this, too. (Might have been the delay while callout check of the delivering IP was underway.)
I haven't looked up rfc-clueless.org's delisting procedure. Some DNSBLs ask you to send mail somewhere making the request. If that's the case, then I suppose you could send the relevent telnet transcript, showing RFC compliance.
People running DNSBLs tend to be cranky and cynical, or become that way if they aren't already. They're also overly busy and wary of comminication with complaining sysadmins as a time sink. However, when all is said and done, they do try to work with sysadmins who _are_ playing by the rules.