Re: sendmail

[Kenneth P. <sh...@we...>]

On Sun, 17 Jun 2001 15:51:08 -0300, Rodolfo J. Paiz wrote:

>At 6/15/01 09:31 AM -0700, you wrote:
>
>>Works well here. I use it with the latest qpopper
>>(http://www.qpopper.org) which can be configured to use DRAC. I've got
>>source RPM's for both at http://www.sewingwitch.com/ken/SRPMS/. You
>>just need to add the following to your sendmail.mc:
>>
>>LOCAL_CONFIG
>># dynamic relay authorization control map
>>Kdrac btree /etc/mail/dracd
>>LOCAL_RULESETS
>>SLocal_check_rcpt
>># allow recent POP/IMAP mail clients to relay
>>R$*                             $: $&{client_addr}
>>R$+                             $: $(drac $1 $: ? $)
>>R?                              $@ ?
>>R$+                             $@ $#OK
>
>You said "add to sendmail.mc" but those look like they belong to 
>sendmail.*cf*. Clarification?

Yeah, it does, doesn't it? ;-) I had exactly the same observation when
I saw it on the DRAC site, and then I went and investigated how the mc
thing works.

The mc file is compiled with m4, a macro processor. m4 has a notion of
"divert", which saves stuff in an indexed-variable for later expansion
until another directive expands it. For example, "divert(1)" takes
stuff following it and puts it in "register 1". "LOCAL_CONFIG" and
"LOCAL_RULESETS" are macros that expand to divert commands and cause
the stuff following them to get stashed in registers that will later be
expanded in the right section in the resulting cf file.

The idea is that, even if you need to write custom rules, you still
shouldn't have to touch the raw cf file. You just put your custom rules
at the end of your mc file, with appropriate directives to indicate
which section of the cf file you want them stuffed into.

>1. Is there, somewhere, full documentation of everything that is recognized 
>in a sendmail.mc file? I've read ***all*** the docs included with sendmail, 
>sendmail-cf, and sendmail-doc RPM's, and of course there's one file with a 
>lot of stuff but not enough, and not clear on many things.

I started with the example provided by Red Hat and the README in the
sendmail-cf directory. I also looked through the m4 sources in the
sendmail-cf directory, and did Google and Deja searches.

>2. Is there, somewhere, simple clear instructions on what needs to be added 
>to the sendmail.mc to use SMTP AUTH? All I could find was:

I'd search through the last couple of years of news:comp.mail.sendmail.
When this feature was introduced, there was a lot of traffic on the
newsgroup about how to get it working. I didn't pay attention as I
wasn't using it, but I remember how popular a topic it was and
continues to be.

>>stock mc enables it. I have MAPS RBL enabled, using
>>"FEATURE(`dnsbl')dns" in my mc file.
>
>I think you meant:
>
>FEATURE(`dnsbl')dnl

Doh!

>right? In any event, I'd like to use both the RBL and the DUL *but* the 
>docs only say that you can use any other DNS-based blocking system with the 
>same FEATURE yet fail to give directions or even one example.

A bit of digging in the m4 sources and looking at the newsgroup
suggests that you just add an optional second and possibly third
parameter to FEATURE:

FEATURE(`dnsbl',`some.other.host',`my custom error message')dnl

>>The stock mc file only allows sendmail access from the loopback
>>interface. You need to comment out a line in the mc file to allow
>>access from your network interfaces. The mc file has a comment telling
>>you what to comment out. (This was done to keep newbies from putting
>>open relays up on broadband connections.)
>
>Kudos to who did this, but it's on 7.1; my 8.11.0 RPM for 7.0 had no such 
>thing.

Red Hat has always included the mc file, but it changed location. It
used to be redhat.mc in the sendmail-cf/cf directory, and recently
moved to /etc/mail/sendmail.mc.

Ken
mailto:sh...@we...
http://www.sewingwitch.com/ken/
[If answering a mailing list posting, please don't cc me your reply. I'll take my answer on the list.]