[Info-vax] Decuserve.org - Anyone know why it's down?

[Bill Gunshannon]

In article <54ac150e$0$42769$c3e8da3$9deca2c3 at news.astraweb.com>,
	JF Mezei <jfmezei.spamnot at vaxination.ca> writes:
> On 15-01-06 10:07, Bill Gunshannon wrote:
> 
>> From: address has niothing to do with any of this.  rogers.com is not
>> what gets sent in the HELO command. rogers.com is in an MX mapping it
>> to an A record.
> 
> Yes it does:
> 
> HELO mtaxxx.yahoo.com
> MAIL FROM: user at rogers.com
> DATA
> <insert email here>
> .

What is it your trying to show here?  The MAIL FROM: merely creates the
>From line in the Email.  Has nothing to do with inter-MTA communications.
That invoves the hostname in the HELO, the IP address it came from and
the reverse mapping provided by a PTR request to the DNS.  You could
put anything in the MAIL FROM: entry, even "Joe's Pool Hall".

> 
> 
>> bell.ca mail exchanger = 10 cluster3.eu.messagelabs.com.
>> bell.ca mail exchanger = 20 cluster3a.eu.messagelabs.com.
> 
> bell.ca is the corporate email server for their staff/execx, not given
> to retail customers who get variety of emails from sympatico, fibe or
> other retail brands.

Well, I have no idea what address Bell Canada customers use but the point
is the same.  The mail domain bell.ca mapps to two different MTA's which
have A Records and PTR Records.

> 
> 
>> take your pick:
>> 
>> ibm.com mail exchanger = 10 e32.co.us.ibm.com.
>> ibm.com mail exchanger = 10 e35.co.us.ibm.com.
>> ibm.com mail exchanger = 10 e4.ny.us.ibm.com.
>> ibm.com mail exchanger = 10 e33.co.us.ibm.com.
>> ibm.com mail exchanger = 10 e31.co.us.ibm.com.
>> ibm.com mail exchanger = 10 e5.ny.us.ibm.com.
>> ibm.com mail exchanger = 10 e3.ny.us.ibm.com.
>> ibm.com mail exchanger = 10 e6.ny.us.ibm.com.
>> ibm.com mail exchanger = 10 e34.co.us.ibm.com.
>> ibm.com mail exchanger = 10 e1.ny.us.ibm.com.
>> ibm.com mail exchanger = 10 e2.ny.us.ibm.com.
> 
> Those are the servers that you may SEND to. But it does not mean that
> those are the only servers you can receive from when someone at IBM
> sends you mail. Many large shops have separate SMTP servers for incoming
> and outgoing mail.
> 
> MX records are only for incoming mail (you sending to them).

I know all this.  You were the one who brought up email domain addresses
like "ibm.com" or, in my case, "cs.uofs.edu".  And I merely pointed out
that SMTP doesn't use that information for anything.  SMTP relies on the
IP Address, the HELO command and the A and PTR Records returned by the DNS.

bill

-- 
Bill Gunshannon          |  de-moc-ra-cy (di mok' ra see) n.  Three wolves
billg999 at cs.scranton.edu |  and a sheep voting on what's for dinner.
University of Scranton   |
Scranton, Pennsylvania   |         #include <std.disclaimer.h>