>> On a related topic, netzero.com has been refusing connections from our SMTP
>> servers. When I queried them the response I got was:
>> have been blocked because we detected probe attempts. Activities like
>> sending mail to non-existent accounts or empty connections would qualify as
>> a "dictionary search" or "probing for valid addresses" and IP's used for
>> such activity would be automatically blocked for a temporary period.
>> Subsequent communications have dealt only with the non-existent accounts.
>> Does blocking us on this basis make any sense? And has anybody else
>> encountered similar issues with netzero? If so, how resolved?
>> In their favor, they did at least respond to me. And it doesn't appear to b=
>> e
>> a robot (or if it is, at least an intelligent one) as it entered into a sor=
>> t
>> of a dialog. This is better than other s who either don't respond ot use a
>> robotic response. Among these are yahoo.com, aol.com, bellsouth.net and
>> charter,net. I list these here not as a form of criticism as I accept the
>> possibility that we may have something configured incorrectly or
>> sub-optimally. My real aim is to find other postmasters who have had simila=
>> r
>> problems with these (or other sites) and discover from them what it is we
>> may need to change.


this is not about netzero (but I am a particular friend of aol for similar reasons.)
To start with, I am maintaining a web shop, so people will eventually complete a form with
their email address, and the server will send them an order confirmation.
We observed a certain rate of failed deliveries (perhaps 1%) due to visitors unable to spell
their own email address correctly.
After some time, I changed the system so that a connection is attempted when the visitor
completes the form, and any 5xx response will result in a "please check your email address"
to the browser. Of course a few domains that are known to bounce later (aol) are not probed.
Recipient servers could consider the same thing as address probing - how tell them?

About responses: I received a "please be patient" type of auto response from aol; when I
mailed them the auto response back a week later, they informed me that they could not find
the original message....

Wolfgang Hamann