mail_host patch

Fri Jun 13 15:17:30 UTC 2003

Vernon Schryver wrote:
>> From: Spike Ilacqua <>
>> ...
>> But this still begs the question of what mail_host should be.  What
>> would you expect in the case of?
>> bar!
>> I *belive* that in all three cases sendmail will set "{mail_host}" to
>> "", as my code will.  Canonify however will give you
>> "" in the last case.  Obviously the ruleset could be writen
>> to give you just about any result.
> I been looking at this issue.
> {mail_host} is for the third case at least in 8.12.10.Beta0.
> Section 3.3 RFC 2821 justifies that choice.
> I see three alternatives:
>   1. use ${mail_host}
>   2. use something like Spike's patch
>   3. a new macro set with a local rule about like
>       Spike's suggestion.
> Looking at the recent Canonify (3) ruleset, I was reminded of
> stuff that sendmail does but that is not done by #2, including
>     - canonicalizing the domain name into a consistant string.
> This matters for whitelisting.  For example, regardless of
> whether a user configures an MUA with
> or, it would be nice if the result were the same.
>     - dealing with pure UUCP paths
> Does this still matter?  Probably somewhere.
>     - dealing with SMTP mail lists
> Does this matter?  Should something reasonable happen with
> a list as a sender?  I don't know.
>     - dealing with stray '\r' characters at the end of the env_from
> value that dccm now receives.  This matters because I've
> seen some spam with the oddity.  It is also trivial to fix.
> #1 has the problem with smart relay hosts that Spike noted as well
> as producing a null value for local senders.
> #3 has compatibility worries.
> My inclination is to change misc/dcc.m4 to create a ${dcc_mail_host}
> macro much as Spike wrote, and have dccm use ${dcc_mail_host} it it
> is not
> null and to fall back on ${mail_host}.
> What do you think?

I am in favor of creating the macro ${dcc_mail_host} as you have indicated
and incorporting that into the I am curious as to what compatibility
issues you see. Would this then entail a new whitelist entry of
dcc_mail_host or would the dccm handle mail_host to mean whatever value is
returned by (${dcc_mail_host}) ?  ${dcc_mail_host} : ${mail_host} ??


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