Hi Kurt,
On 26.03.2008, at 15:03, Kurt A. Schumacher wrote:
...
This is a silly reverse setup. A reverse lookup should only return one hostname, not 20.
... What about the most stupid wanabe Spam-fighter which are very unhappy as in place (e.g. the third-party service provider systems acting with some SC subsidiaries...) which high rate valid messages if certain brain-dead conditions like PTR not matching MX don't match?
There are a lot of E-Mail Providers (i.e. gmx) behaving like this already.
If A, PTR, MX and HELO are not exactly the same (all four) the message is marked as SPAM. There are pro's and cons for this...
I would not rate E-Mails solely because of those four points, but that's only me....
CU Tobias
Salut, Tobias,
On Wed, 26 Mar 2008 15:52:04 +0100, Tobias Göller wrote:
There are a lot of E-Mail Providers (i.e. gmx) behaving like this already.
If A, PTR, MX and HELO are not exactly the same (all four) the message is marked as SPAM. There are pro's and cons for this...
This is an entirely different question. The question here is:
1. is there an A record for the host advertised in HELO/EHLO? (sensible question) 2. Is there an A record for the PTR which matches the A record? (Questionable) 3. Potentially even: is the domain of the PTR record the one we're sending mail for? (WRONG! See e.g. the large hosteurope mail setups for lots of virtual sites, etc. pp.) 4. Is the sender an MX for the domain? (WRONG! Especially in large setups, it is a very bad idea to use the same servers for submission and receiving, especially due to the entirely different requirements. Even hatemail does not do this. If you want to do such checks, there is SPF.)
There are more sensible ways to waste our mail servers' time than to check PTR records for bizarre requirements which are never met.
Tonnerre
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Tobias Göller -
Tonnerre Lombard