Thinking about spam rejection and abuse addresses
Somewhat recently we got a spate of spam messages to our abuse address, which set me to thinking about the mostly theoretical issue of how to treat email to it.
(It's a mostly theoretical issue for us because the volume of spam and other email to our abuse address is very low in general, so we're not at all likely to change anything about it.)
On the one hand, visible spam rejection of email to abuse addresses is one of the things that really gets on people's nerves; it's famous for rejecting real spam complaints because, of course, they contain spam. Your spam, that people are trying to complain about.
On the other hand, email to abuse is going to go through our spam scoring system and get tagged if the system thinks it's spam. Pretty much everyone here either discards spam-tagged email outright or filters it to a separate folder. My mail filtering deliberately excludes email to abuse (among a few other things), but I don't know if anyone else either bothered or even thought of it; it's not necessarily something that comes to mind when you're setting up personal email filtering.
And finally, I can't think of any actual real email to our abuse address that we've gotten in the last five years or so (since I moved to here). It's all been spam. So as a practical matter, any filtering or rejection that we do on abuse email is unlikely to affect real complaints, because we don't get real complaints (hopefully because our users and machines don't generate spam, as opposed to people just not complaining about it).
(The other aspect of email to our abuse address is that I suspect most people are going to complaint to the central university-wide abuse address instead of abuse at our specific subdomain. The central people will then get in touch with us through our internal contact address, not our abuse address.)
This is of course a specific instance of the general spam rejection versus spam filtering dilemma. If you reject email people at least know; if you filter, there's at least a theoretical chance that you'll recover from filtering mistakes. The stakes are higher for the abuse address because it is one of the addresses that has a very high chance of false positives (non-spam classified as spam).
The most pragmatic thing to do in a situation like this is to apply spam-filtering to your abuse address. This blackholes real spam to keep it from bothering people while carefully not saying anything to real senders who had their messages misclassified. But this pragmatism sort of bothers me because it's lying to real senders just to pacify them (their email is being ignored either way but you're deliberately doing it silently so they don't know). It would be more honest to use spam rejection on the abuse address, and it might do some good to reduce the level of spam. If legitimate email to your abuse address really is vanishingly rare, it also shouldn't affect very many people.
So what's the right answer? I have no idea.
(My current approach of exempting the abuse address from my personal filtering would not be viable if it got a lot of spam. At that point I would probably remove the exemption and let spam-tagged email to the abuse address get quietly filtered away, mostly because it's easier than trying to persuade everyone that maybe we should do spam rejection for email to abuse.)