On Fri, 14 May 2004, Jon Kyme wrote:
"Tony Finch" <dot(_at_)dotat(_dot_)at>>
On Fri, 14 May 2004, John Leslie wrote:
I find it worrysome that we're proposing things like
"v=spf1 mx -all"
meaning that the receiving MTA is expected to pull the entire list
of
MX records, resolve them to IP addresses, and check whether the one
IP address of interest is in that set.
Most MTAs do this already (apart from the last step, which is a
nugatory
amount of work). Why is it worrying?
When receiving mail? Are you sure?
Yes, in order to verify that the domains in the envelope addresses
actually exist. This has been a standard anti-spam technique for many
years.
Well you do seem very sure, so how do we explain:
220 mc8-f13.hotmail.com Microsoft ESMTP MAIL Service, Version:
5.0.2195.6824 ready at Fri, 14 May 2004 07:26:11 -0700
ehlo there
250-mc8-f13.hotmail.com (02.04.01.0013) Hello [nnn.nnn.nnn.nnn]
250 OK
mail from: gfgfg(_at_)hkakasgcbasjfd(_dot_)com
250 gfgfg(_at_)hkakasgcbasjfd(_dot_)com(_dot_)(_dot_)(_dot_)(_dot_)Sender OK
or:
220 YSmtp mta133.mail.sc5.yahoo.com ESMTP service ready
ehlo there
250-mta133.mail.sc5.yahoo.com
mail from: <gfgfg(_at_)hkakasgcbasjfd(_dot_)com>
250 sender <gfgfg(_at_)hkakasgcbasjfd(_dot_)com> ok
Perhaps you're thinking of:
220 chiark.greenend.org.uk sauce-smtpd ESMTP ready [Pleased]
ehlo there
250-chiark.greenend.org.uk hello
250-SIZE
250-8BITMIME
250 PIPELINING
mail from: <gfgfg(_at_)hkakasgcbasjfd(_dot_)com>
250 Warning! Rejection likely: invalid MAIL-FROM: Error during DNS MX
lookup for hkakasgcbasjfd.com: No such domain