Unwanted e-mail and slow thinking
Jul. 29th, 2018 07:45 am![[personal profile]](https://www.dreamwidth.org/img/silk/identity/user.png){kind=small}
mtbcLast year I mentioned that I do not graylist incoming e-mail because of how some senders retry from different hosts but I do use IP blacklists to block MTAs. This approach has been quite effective though in recent weeks more spam in East Asian languages has been getting through and brought my anti-spam arrangements back to mind.
I am intelligent and, about some technical things, quite knowledgeable. Despite this, sometimes it takes me a long time to see the obvious. The example in this case is the synergy between graylisting and blacklisting: the very simple point that I could well receive much less spam if I graylist for long enough for senders to be added to the blacklists for which I fetch hourly updates.
Such a use of graylisting does not require the typical specificity about the envelope sender and recipient: I do not care who e-mails whom, I care more that the MTA is attempting a delivery to anybody at all. I wonder if there is a configuration option for that. If not, graylisting by sending IP only may be simple enough that I can arrange it between pfctl -t and cron without a fancy dæmon if a failure to connect is taken rather like a 4xx SMTP response.
I am intelligent and, about some technical things, quite knowledgeable. Despite this, sometimes it takes me a long time to see the obvious. The example in this case is the synergy between graylisting and blacklisting: the very simple point that I could well receive much less spam if I graylist for long enough for senders to be added to the blacklists for which I fetch hourly updates.
Such a use of graylisting does not require the typical specificity about the envelope sender and recipient: I do not care who e-mails whom, I care more that the MTA is attempting a delivery to anybody at all. I wonder if there is a configuration option for that. If not, graylisting by sending IP only may be simple enough that I can arrange it between pfctl -t and cron without a fancy dæmon if a failure to connect is taken rather like a 4xx SMTP response.
