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Sendmail 8.9.0 relay question

Posted on 1998-10-28
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Last Modified: 2013-12-15
Hi,

I have a sendmail configuration question:

I just upgraded to sendmail 8.9.0 and realized that the configuration
has changed from earlier versions. I went to the sendmail faq site
(http://www.sendmail.org/faq/) where they have a very nice tutorial on
sendmail. My particular problem was that the new version of sendmail
turns off relaying for other hosts by *default*, which means that
not only spammers will have a hard time to abuse your host for relaying
spam, but also accountholders on your system who use popmail will have
trouble to get their outbound mail relayed.

Anyway, on that faq there is a section that deals with this issue:
http://www.sendmail.org/tips/relaying.html
and it mentions a /etc/mail/relay-domains file, and "features" that can
be added. How do I optimally configure this
file such that mail works properly for popmail clients, no matter where
they come from (I have a few coming in from outside of our domain using
different ISP's, which may change from time to time)?
They do not show an example of the correct syntax of this relay-domains
file, and was wondering if someone here can tell me how to set this file up
properly.


Right now I have:

FEATURE(promiscuous_relay)
FEATURE(rbl)

I am not even sure if this is the correct syntax.
FEATURE(promiscuous_relay) is supposed to let everyone use my
machine for relay (including spammers) and FEATURE(rbl) is supposed
to deny service to sites listed on the public spamming blacklist at
http://maps.vix.com/ (what a great idea!).  I am not sure about the
syntax and also not sure if I need other configurations to make this
work. Any help with this would be appreciated...
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Question by:demeler
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by:
henckens earned 150 total points
Comment Utility
The relay-domains is the right answer.  The format can be as follows

1.1.1.
(for a whole subnet)
domain.com
(for a whole domain)
1.1.1.1
(for a single ip address)

Just start hit enter after every line, so it's listed vertically.  That's all there is to it.  If you want to give someone relay permissions outside of the domain, you can simply add the dialinlocation.domain.com to it.

Activate it in your sendmail.cf file in the following line
FR-o /path/relay-domains

Much luck,
Andres
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Author Comment

by:demeler
Comment Utility
Your answer only partially answers my question:

I don't want to manually add each possible domain from which someone may be calling, since this changes all the time for roaming users. I basically want to leave the system open for
all domains, except for those blacklisted on maps.vix.com.
I understand that this can be set up such that sendmail automatically retrieves the latest database from maps.vix.com
and disables relaying for those sites. How do I do it? Also
in /etc/mail/relay-domains? How do I use the FEATURE(xxx) command?

Thanks!!
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