Author: Renaud Allard Date: To: Peter Bowyer CC: Exim, Users Subject: Re: [exim] OT(?): SRS vs. SORBS sending mails with '<>' sender
Peter Bowyer wrote: > On 05/01/07, Renaud Allard <renaud@???> wrote:
>> Peter Bowyer wrote:
>>> On 05/01/07, Renaud Allard <renaud@???> wrote:
>>>> If you'd ask for a personal advise, SORBS is nothing to be trusted as a
>>>> blacklist.
>>> They have 17 different lists. Is this broad-brush 'advice' to be
>>> applied to all 17?
>>>
>> Unfortunately, yes. :(
>
> You've used them all, and experienced FPs? What about dul?
>
DUL is probably the most broken one. Why? because unless you are an
american ISP, you are not really "required" to give good info about your
dynamic and non dynamic ranges. That means most european (and probably
others too) ranges are just not declared the way they should. I know
this is a shame and that shouldn't be that way, but it is done that way.
On many european networks, you just are blacklisted unless you do a step
to prove your you are not (correct RDNS, which should be required anyway
in my mind, + a contact and mandatory registration with sorbs).
After all, if all mail servers were required to have matching HELO, PTR
and A records, blocking spam would be almost trivial (and I must admit
those should be mandatory requirement for mail servers nowadays).
>> I am sorry to tell that, but is you use sorbs as a first line of defense
>> and reject with 5xx on this only, be prepared to reject a bunch of
>> legitimate mails.
>> I prefer to use them on a basis like "if you are listed on sorbs spam
>> and the callout doesn't verify, and you are attaching an image, just
>> forget about sending me mail". So they are useful, no doubt about this,
>> but just cannot be trusted.
>
> What's you're evidence for this? Broken down by the 17 separate lists.
>
Experience with most of them. Unfortunately, I cannot give you any more
evidence because I stopped using sorbs as a first line defense quite
some years ago.
