Date: Tue, 28 Jul 1998 22:26:00 -0400 (EDT) From: CyberPeasant <djv@bedford.net> To: sderdau@bit-net.com (Stephen Derdau) Cc: freebsd-questions@FreeBSD.ORG Subject: Re: email question. Message-ID: <199807290226.WAA22986@lucy.bedford.net> In-Reply-To: <Pine.OSF.3.95.980728120246.15623A-100000@mail.bit-net.com> from Stephen Derdau at "Jul 28, 98 12:28:30 pm"
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Stephen Derdau wrote: > Why would email sent by a user sderdau%mcl > be delivered and showing from sderdau@mcl instead of > sderdau%mcl@qualified.domain.com. This sounds strange. I can answer the question: "Why would email sent to user sderdau%mcl@q.d.c be sent to sderdau@mcl?" The answer to /that/ question is that the mail system sends to q.d.c; q.d.c looks at the stuff to the left of the @. It substitutes a @ for the right-most % and looks at it again. If there's no @, it's a local user; if there's a @ it sends it off (relays it). This continues until all the %s are eaten. Lots of machines won't do this: it's a form of relaying that spammers have abused. Its legitimate use is to work around problems. Suppose we want to send to A@B. We are at host X. Host B is down or unreachable, has no MX host. But host X is going to go down soon, (It's a laptop? It's running NT? The Feds are at the door?). We know that mail to host C will either get to C or be MX'd somewhere. So we send mail to A%B@C. Getting it to B is now C's problem. > Pointers in the right direction appreciated. > I know this is probably a sendmail question . Just hoping > someone with great expertise wouldn't mind answering it. No great expertise here, but my answer to the question you didn't ask :) is a clue to what's going on, if the question you /did/ ask is the real question. Dave -- Sancho Panza: `Microsoft Windows NT Server is the most secure network operating system available.' Don Quixote: `You are mistaken, Sancho.' To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-questions" in the body of the message
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