Re: [exim4] Testing and making sense of smtp output
Brian <ad44@cityscape.co.uk> writes:
>> > An address literal is not the same as an IP address. An MTA should not
>> > be rejecting mail on the basis that the HELO is an address literal.
>>
>> Oh, then what is it?
>
> Using an example from RFC5321, an address literal is [123.255.37.2]. An
> IP address would presumably be 123.255.37.2.
Hm, there's not much of a difference, or is there? It's still an IP
address and being used as one, only inside brackets for unknown reasons.
Using IP literals when sending email used to work long ago ...
>> > It's probably academic what the HELO is most of the time. Many ISPs
>> > will accept any old rubbish for it.
>>
>> That's a misconfiguration they should fix.
>
> You tell them. :) They might say they are not breaking any RFCs and will
> accept any mail they feel like doing.
I'm not sure if they aren't. The RFCs specify what the HELO must be
like, and you could either argue that they comply with RFCs' policy that
you should accept as much as possible or that you're breaking RFCs by
using invalid HELO strings.
At least they are supporting others in breaking RFCs, and I wonder how
that could not be against their own interests. In any case, it
classifies them as (at least potentially very) unreliable.
--
Again we must be afraid of speaking of daemons for fear that daemons
might swallow us. Finally, this fear has become reasonable.
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