Re: [exim] BATV & SPF

Góra strony
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Autor: David Saez Padros
Data:  
Dla: exim-users
Temat: Re: [exim] BATV & SPF
Hi !!

>> Just playing with BATV i noticed that it could conflict with some (mine
>> in that case) SPF setups. If i publish SPF records like "v=spf1
>> redirect=%{l}._spf.ols.es" which use the local part of the envelope
>> sender to generate a new dns request then batv encoded addresses like
>> prvs=david/0297929b3b@??? produce a dns query on
>> prvs=david/0297929b3b._spf.ols.es which include two forbiden charactes
>> (= and /)
>
> Those characters are absolutely fine in a DNS query. They aren't valid in
> host names or mail domains, but then neither is "_". DNS names are a
> superset of host names.


If they are not valid on hostnames maybe dns queries trying to get a
txt record for such an invalid hostname may fail, either at the client
or at the server side. Anyway looks like some software insist on having
valid hostnames on dns queries, in that case the verifier at
auth-results@??? gives that information:

----------------------------------------------------------
mail-from check details:
----------------------------------------------------------
Result: fail (malformed domain)
Address: david/0297929b3b@???
Header: verifier.port25.com smtp.mail=prvs=david/0297929b3b@???;
mfrom=fail (malformed domain);

I just suposed that the error comes from the "/" introduced by batv
altough other spf check tools like dnsreport work well with batv
signed emails:

http://www.dnsreport.com/tools/spf.ch?server=prvs%3Ddavid%2F0297929b3b%40ols.es&ip=213.195.75.88

--
Best regards ....

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