Just wanted to second this. While individuals would rarely send through
email servers set up this way, mid sized to enterprise businesses can.
On 12/13/2016 1:53 PM, Mikkel C. Simonsen wrote:
OpenBSD lists wrote:
Most of the spam I've received from marketing companies tends to come
from send-only servers (looking at the user-agent of the sending
server its some kind of Python library intended for just sending
pre-formatted messages to a list of recipients).
What I've done is constructed a script that while spmad is stuttering
their connection, it connects back to the sending server on port 25
and executes an EHLO. If the sending server doesn't respond to the
EHLO, it runs pfctl to add that server's address to a block list.
That will block a LOT of legitimate e-mail also. Including
semi-legitimate e-mails like this one... Why should all e-mail servers
accept connections from the outside?
Mikkel
