On Mon, 2006-11-06 at 22:49 +0100, Renaud Allard wrote: > I have set some rules that stores helo names in a mysql database and I
> used it to block sites when the helo domain (only the domain part)
> changed within small time intervals. However, it seems that some (many?)
> legit mailservers behave this way. So I would advise you against doing
> this. Changing the helo for the same IP is a very bad idea IMHO, but
> blocking on this only will reject legit mails.
When connecting manually to what seems to be a recalcitrant server, I'll
often type 'helo me' -- and if I _do_ attempt to type my own hostname
I'll probably mistype it a large proportion of the time anyway.
I consider those to be 'valid' cases in which the same IP address will
connect with different greetings -- in addition to the point about
people deliberately varying their greeting according to the domain of
the sender.
