Dear Google,
Here’s a Wikipedia article for you: Greylisting.
After you’ve read that, then consider the error message I always get for my groups.google.com account when you disable mail sending to me due to “bouncing”:
Bounce status Your email address is currently flagged as bouncing. For additional information or to correct this, view your email status here [link].
“Google tried to deliver your message, but it was rejected by the server for the recipient domain haxx.se by [mailserver]. The error that the other server returned was: 451 4.7.1 Greylisting in action, please come back later”
See, even the error message spells out what it is all about!
Thanks to this feature of Google groups, I cannot participate in any such lists/groups for as long as I keep my greylisting activated since it’ll keep disabling mail delivery to me.
Enabling greylisting decreased my spam flood to roughly a third of the previous volume (and now I’m at 500-1000 spam emails/day) so I’m not ready to disable it yet. I just have to not use google groups.
Update: I threw in the towel and I now whitelist google.com servers to get around this problem…
Google Groups are about as badly implemented as Google Reader, and are getting about the same amount of love. I fully expect them to be discontinued in the next round of cuts at Google.
I quickly read the description of greylisting. It sounds like it mildly protects the person using the greylisting, mildly harms the internet at large, and would severely harm the internet at large if everyone did it (I’m a utilitarian, but Kant’s universalisabilty test is a good rule of thumb). Additionally, if everyone did it, it would be made entirely redundant by workarounds by the spammers (which seems to already be happening) and we’d be left with a useless greylisting legacy that would take a long time to repair.
So, (and this happens pretty rarely) I’m supporting Google on this one.
@voracity: you do miss the point though that it is a 4xx transitional response that should be retried (yes the specs say so). There are many other reasons for transitional responses than greylisting so even if I would be a “bad guy” here (and I’ll let others judge that), it doesn’t make them right.