[ale] [OT] Sendmail (?) woes

[Greg]

per O'Reilly's bat book "Sendmail"
p.317

Many older MTA's on the network ignore MX records, and some Sun sites
wrongly run the non-MX version of sendmail (that is they should use
/usr/lib/sendmail.mx).  Because of this, you will occasionally find some
sites that insist on sending mail to a host even though that host has been
explicitly MX'd to another."

It goes on to say that "failure to obey MX records is a clear violation of
published network protocols. RFC1123, *Host Requirements*, section 5.3.5,
notes that obeying MX records is mandatory."

translation: some Sun sites send mail to the *host* (i.e. the MTA - not the
MUA), that sent the mail i.e. your sendmail host name, which is what you are
indicating.

Also, fudging your "From;" line is contradictory to RFC1123 (which modified
RFC822).

Another possible solution also is on p.544 it talks about "a common problem
with SysV versions of /bin/mail is its annoying habit of prepending a "From
" line to the beginning of each message, even if one is there already."

Another thing is that Sendmail uses the concept of an *envelope*, which is
NOT the same as header info - so Sendmail could not be changing it's
*envelope* regardless of your header info.

A slight perusal of the Sendmail book also revealed several other things
that could be wrong.  Masquerading was a whole section.  The book was around
1020 pages so there is a lot to it.  I would suggest a perusal of it to help
in fixing this problem and also to help in administering Sendmail (a huge
beast in and of itself).

Daniel J. Bernstein.  Associate Math Professsor at Univ. of Chicago.  Went
to Berkeley, CA for undergrad degree.  Wrote qmail, tinydns, and many
articles on stuff that is broke w/ regards to the Internet.

website is at http://cr.yp.to/djb.html

good stuff, especially daemontools, ucspi, etc.  Writes also on the many
many problems of Sendmail and BIND.

Greg

> -----Original Message-----
> From: ale-admin at ale.org [mailto:ale-admin at ale.org]On Behalf Of Joe
> Sent: Wednesday, January 22, 2003 4:24 PM
> To: ale at ale.org
> Subject: Re: [ale] [OT] Sendmail (?) woes
>
>
> "Greg" <runman at speedfactory.net> writes:
>
> > well, the original question of your post -
> >
> > > > Why does my delivery agent say
> "From:<joe at orado.localdomain.private>"
> > > > when I'm explicitly setting the From: line to
> "jknapka at earthlink.net",
> > > > (below)? Is this a sendmail.cf thing (shudder)?
>
> I'm really confused. Or, more likely, not making myself clear.
> Earthlink has nothing to do with this problem except that I prefer to
> receive mail at my Earthlink mailbox, and therefore I set my From:
> address to "jknapka at earthlink.net" in my mail client.  I'm not going
> through Earthlink's SMTPs server; my local sendmail is trying to talk
> directly to "mx3.sun.com" and making a hash of it. It seems my
> sendmail daemon is identifying itself to mx3.sun.com as
> "orado.localdomain.private" in the From: line of the outgoing mail,
> which would be right and proper, as that is its hostname.
>
> *However*, I thought that the "From:" line should always be the From:
> line in the mail headers; transport agents aren't (IIRC) supposed to
> touch a From: line, only add one if there's none. Furthermore, I have
> recently explicitly instructed my sendmail to "masquerade" as
> "kneuro.net" (an unrelated domain I own), yet *still* it tells
> mx3.sun.com that it's "orado.localdomain.private".  I am apparently
> missing something important.
>
> > I think that djb goes into some of this stuff on his website, too.
>
> Who is djb?
>
> Thanks,
>
> -- Joe
> _______________________________________________
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> Ale at ale.org
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>

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