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List:       postfix-users
Subject:    Re: Preferred/maintained greylisting options?
From:       Charles Sprickman <css () morefoo ! com>
Date:       2020-05-24 20:05:15
Message-ID: 7A7ABD17-DD1D-46D4-A472-3BA1D52BE281 () morefoo ! com
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> On May 24, 2020, at 3:59 PM, Laura Smith <n5d9xq3ti233xiyif2vp@protonmail.ch> \
> wrote: 
> > 
> > I've been sort of opposed to greylisting in the past due to a userbase that's \
> > sensitive to delays, but… the spam is worse. 
> 
> 
> IMHO Greylisting is rather pointless. Its a blunt tool, and not only that it does \
> that unforgivable thing of annoying genuine people. 
> I would hazard a guess that if you are being innundated with spam, then your RBL \
> setup is less than adequate. Both the choice of RBLs  ***AND*** the correct \
> configuration thereof is critical.

As I described in my original email, this isn't a failure of RBL setup. I'm just \
being inundated with:

- Correctly configured hosts that don't fail any obvious protocol checks
- Hosts that are not on any RBLs until 5-10 minutes after delivering

As I see it, I have limited options:

- Do more filtering on content (blech - these only score +1 or so in SA)
- Delay the mail (from non-whitelisted senders) until the hosts are listed.

> I should also add that you should not be afraid to pay for access. The good lists \
> will (a) block you if you hammer them with high volumes of requests (b) save some \
> of their better content (or new innovations) for their paid subscribers.

I've trialed the major ones with no improvement. The greylisting suggestion came from \
Abusix because they looked up a day of "leaks" and found they were simply delivering \
before they were being listed.

> RBLs these days are pretty darn good, with everything setup correctly you can \
> easily be in the very high 90-percentiles of catching spam and pretty much zero \
> false-positives.

Sadly, we seem to be at the head of most spammer's lists. One of these "paid" \
services should give us free access in return for a spamtrap. :)

It's also incredibly obvious there are some colos that are catering to these people, \
esp. that firm out of Buffalo…

Charles

> 


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