On Tue, 8 Mar 2005, Miles Libbey wrote:
I was talking to an MTA developer at MAAWG last week, and he thinks that there
are 'a lot' of legit domains that HELO with non-domain text (garbage text).
Regardless of the RFC compliance of this action (and what 'a lot'
constitutes), I thought it might be interesting to find some data on this
I did some analysis of this in December. According to my numbers "a lot"
is about 1/3 of legitimate email senders, and a rather higher proportion
of spam and viruses.
This doesn't include syntactically invalid HELO domains - Exim rejects
those - and it doesn't include domain literals, which are also frequently
f.a.n.finch <dot(_at_)dotat(_dot_)at> http://dotat.at/
ROCKALL MALIN: NORTHWESTERLY 4 OR 5, BUT VARIABLE 3 OR 4 IN SOUTHEAST ROCKALL
AT FIRST. RAIN OR DRIZZLE. MODERATE OR GOOD.