At 5:10 pm -0400 30/5/2011, Hector Santos wrote:
So basically, on the first DATA attempt our data filter returned a
FAIL=451 which was a greylist filter script, the transaction and
state was cleared with RSET. Then during the 2nd attempt the client
was able to get by the initial rejection.
If you read a bit further in to section 220.127.116.11 it says:
effectively equivalent to a NOOP (i.e., it has no effect) if issued
immediately after EHLO, before EHLO is issued in the session, after
an end of data indicator has been sent and acknowledged, or
immediately before a QUIT.
If your server is adhering to the standard, you would still have the
same problem even if the spammer left out the RSET, or replaced it
with a NOOP, so this isn't a problem with RSET.