Milter-greylist

More curious than anything else, it doesn't seem to be an actual problem.

In /var/log/maillog, I see many instances of incoming failures that go on
for sometimes over an hour, at intervals of 1-6 seconds, like this example:

Nov  7 10:32:15 fcshome sendmail[29404]: uA7FW8Wx029404: [49.64.41.187] did not issue MAIL/EXPN/VRFY/ETRN during connection to MTA
Nov  7 10:32:15 fcshome sendmail[29406]: uA7FW90o029406: [49.64.41.187] did not issue MAIL/EXPN/VRFY/ETRN during connection to MTA

this particular string went on for about a half hour. some are shorter,
some are longer. 

all the ones I've checked (using the host command) don't resolve.

As I have sendmail configured to drop such things they don't seem to
cause any actual problem, but since I see many sets of similar events
every day I wonder what's going on. Is this someone's spam engine gone
whacko, or someone trying to DOS me, or what?

Thanks in advance, Information welcome!

Fred
-- 
---- Fred Smith -- fredex@... -----------------------------
                         God made him who had no sin
                      to be sin for us, so that in him
                 we might become the righteousness of God."
--------------------------- Corinthians 5:21 ---------------------------------