Is greylisting currently a maintenance-free answer?

[washmail]

This thread branches off in new directions from the previous thread "Tackling the world's worst..." (viewing from post #25 would suffice) at http://forum.spamcop.net/forums/index.php?...9152&st=20#

spamjadoo[dot]com hasn't responded to my long list of questions, so I've looked beyond for other automated, harmless bouncing options.

It appears to me that the main tool of advantage in these type of spam eradicating options on offer is what is referred to as greylisting at server level, a system used to technically identify spam resulting in high eradication success rates.

I found a number of articles which discuss this method. I recommend starting with the short article at greylisting[dot]org which also debates it's long term effectiveness.

There seems to be quite a bit of software available for server level implementation, but not much could be found regarding individual MX outsourcing to services offering this method.

I'm awaiting a response from the only other one I've found so far that seems to fit the need - seiretto[dot]com in the UK.

But the question is does greylisting deliver what it promises?

[StevenUnderwood]

But the question is does greylisting deliver what it promises?

SpamCop also offers a greylisting option. I have very little use for it as the other options let less than 1% of spam through to my inbox, I like to receive the spam for reporting, and a large percentage of my spam is forwarded from gmail and yahoo accounts, not directly to my spamcop accounts.

I did try it a couple of weeks ago for a weekend and no spam (except those forwarded accounts) even got into my HeldMail folder.

The effectiveness of greylisting could be affected by the windows for when the message needs to be resent. If the window starts too soon and is affecting a spammers success, that spammer could simply setup his software to send the same list a second time when the first run is done and the message will get through. If the window lasts too long, that spammer may get through with future runs if it uses the same sender address. Those windows will also affect valid messages if they are not set effectively.

In the future, spammers software may learn to deal with these rejections, again, if greylisting starts to affect their income.

[washmail]

The effectiveness of greylisting could be affected by the windows for when the message needs to be resent. If the window starts too soon and is affecting a spammers success, that spammer could simply setup his software to send the same list a second time when the first run is done and the message will get through. If the window lasts too long, that spammer may get through with future runs if it uses the same sender address.

As best as I can understand it, spamjadoo[dot]com appears to claim that they can accurately identify resent spam based on the reply's delay duration, but what you explain above makes it (IMO) likely that such ability would be short lived at best.

Those windows will also affect valid messages if they are not set effectively.

Fortunately senders of any such false positives would at least receive a server response.

I am unfortunately unable to participate further.

Best wishes for all your anti-spam endevours.