Mailertable - Using comma to simulate MX

Ed Spyhill

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Oct 19, 2004, 4:46:52 PM10/19/04

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Quick question. In our DMZ we do not have access to MX records.
Our mailertables use IP addresses delimited with a comma to
simulate a DNS round-robin MX record.

insideDomain.com esmtp:[123.45.67.121],[123.45.67.123]

This returns a random IP of the two listed.

I think we can use a colon or a semi-colon for a weighted
DNS MX record.

What are all the punctuation marks, etc that can be used
in the mailertable? Searched the archives and the Internet
but could not find any docs.

Thank you,

Ed

Andrzej Adam Filip

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Oct 19, 2004, 5:08:00 PM10/19/04

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insideDomain.com esmtp:[123.45.67.121]:[123.45.67.123]

It will work for esmtp, smtp, smtp8, relay, dsmtp.
The above mailers will accept ':' separated list treat it "try in this
sequence". AFAIR it documented somewhere but it is hard to find from
mailertable perspective.

--
Andrzej [en:Andrew] Adam Filip an...@priv.onet.pl an...@xl.wp.pl
Home Page http://anfi.homeunix.net/ [ PageRank 6 ]
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edsp...@yahoo.com

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Oct 19, 2004, 9:44:03 PM10/19/04

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Andrew,

AFAIK, the ':' will act like a weighted MX record.
Using the ':' is the same as:
DNS-MX-name IN MX 10 relay1.domain.com
DNS-MX-name IN MX 40 relay2.domain.com

And using ',' (comma) is the same as a round-robin MX:

DNS-MX-name IN MX 10 relay1.domain.com
DNS-MX-name IN MX 10 relay2.domain.com

I just wanted to ensure we have only the two options,
the comma and colon.

Thank you for the example.

Ed

Claus Aßmann

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Oct 19, 2004, 10:45:05 PM10/19/04

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wrote:

> AFAIK, the ':' will act like a weighted MX record.

> And using ',' (comma) is the same as a round-robin MX:

Note: only ':' is documented behavior and only for listing
hosts for IPC mailers, see doc/op/op.*:

If the mailer is the built-in IPC mailer, the host may
be a colon-separated list of hosts that are searched
in order for the first working address (exactly like MX
records).

Using ':' in other places or using ',' means that you rely on an
undocumented implementation detail which may or may not change at
any time.

The proper way to implement what you want is to use MX records.
--
A: Maybe because some people are too annoyed by top-posting.
Q: Why do I not get an answer to my question(s)?
A: Because it messes up the order in which people normally read text.
Q: Why is top-posting such a bad thing?

Dennis Peterson

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Oct 20, 2004, 1:36:05 AM10/20/04

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Claus Aßmann wrote:
> wrote:
>
>
>>AFAIK, the ':' will act like a weighted MX record.
>
>
>>And using ',' (comma) is the same as a round-robin MX:
>
>
>
> Note: only ':' is documented behavior and only for listing
> hosts for IPC mailers, see doc/op/op.*:
>
> If the mailer is the built-in IPC mailer, the host may
> be a colon-separated list of hosts that are searched
> in order for the first working address (exactly like MX
> records).
>
> Using ':' in other places or using ',' means that you rely on an
> undocumented implementation detail which may or may not change at
> any time.
>
> The proper way to implement what you want is to use MX records.

Note to self: come the dawn go out and discover what the hell an IPC mailer is.
It might be important. Or not.

dp

Jochen Bern

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Oct 20, 2004, 4:45:31 AM10/20/04

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Dennis Peterson wrote:
> Note to self: come the dawn go out and discover what the hell an IPC
> mailer is. It might be important. Or not.

Lemme save the (start of the) day for you:

| # grep IPC /etc/mail/sendmail.cf
| Msmtp, P=[IPC], F=mDFMuX, S=EnvFromSMTP/HdrFromSMTP,
R=EnvToSMTP, E=\r\n, L=990,
| Mesmtp, P=[IPC], F=mDFMuXa, S=EnvFromSMTP/HdrFromSMTP,
R=EnvToSMTP, E=\r\n, L=990,
| Msmtp8, P=[IPC], F=mDFMuX8, S=EnvFromSMTP/HdrFromSMTP,
R=EnvToSMTP, E=\r\n, L=990,
| Mdsmtp, P=[IPC], F=mDFMuXa%, S=EnvFromSMTP/HdrFromSMTP,
R=EnvToSMTP, E=\r\n, L=990,
| Mrelay, P=[IPC], F=mDFMuXa8, S=EnvFromSMTP/HdrFromSMTP,
R=MasqSMTP, E=\r\n, L=2040,

Regards,
J. Bern

edspyhill

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Oct 20, 2004, 9:53:53 PM10/20/04

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"Claus Aßmann" <ca+sendmail(-no-copies-please)@mine.informatik.uni-kiel.de>
wrote in message news:cl4jfh$h4o$1...@zardoc.esmtp.org...

Claus,

Thank you. I'll find out why we were denied MX records in the DMZ.
I'll note the unsupported used of commas and pass the info to my
co-workers.

Ed S.

edspyhill

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Oct 20, 2004, 9:56:36 PM10/20/04

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"Andrzej Adam Filip ( http://anfi.homeunix.net/ )" <an...@priv.onet.pl> wrote
in message news:cl3vln$ouj$1...@anfi.homeunix.com...

Andrzej,

Thank you for the reply and information.

Ed S.

aaron....@gmail.com

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Oct 19, 2011, 7:54:59 PM10/19/11

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Just wanted to say this thread came in major handy for me in production =)So happy it was like number one on a Google search for such an obscure topic!!