Noel Jones wrote:
On 2/23/2015 10:33 AM, Charles Orth wrote:
Hi All,
At this time, we're relying on extended error code 5.2.1 to drop the
connection.
I suppose you're referring to the 521 reply code.
We'd like to a more robust set of extended error codes (RFC5248)
which also drop the connection.
Why?
Has there been any discussion on Postfix providing a new feature
where we can configure specific
extended status codes to drop the connection?
No. Real mail servers may respond poorly to abrupt disconnections.
Many will interpret a disconnect as a "lost connection" and retry
the delivery again and again, turning a single rejection into
hundreds. Get enough senders doing this and you effectively DOS
yourself.
It's generally safe to hang up on spambots. There's already support
for that in postscreen and the rbl reject codes.
-- Noel Jones
Yes 521 error code.... didn't proof read my message before sending it out.
Unfortunately, the RBL feature is too primitive for our needs.
With billions of messages daily we already deal with both large and
small hosting companies that don't interpret closing the connection
as a lost connection. If this was the case, we'd have escalation issues
daily.
