Partially? disabling check_mail in sendmail 8.8

Partially? disabling check_mail in sendmail 8.8

Post by Glenn Henness » Wed, 18 Feb 1998 04:00:00



        I'm converting from an IBM RS6000 box to a Linux box for doing email
within my department and have hit a snag. In sendmail 8.8 there are rulesets
which prevent linux from being used as a mail relay. The vast majority of my
users use Eudora and therefore look as though they are using the system as a
relay. I know that I can add entries to the ip_allow file for my domain but I
have users who do this from home through whatever ISP they have chosen which
makes creating an ip_allow file a difficult task. Can I just comment out the
check_mail rules and have sendmail work or is there something better that I
can do?
        Thanks.
Glenn

 
 
 

Partially? disabling check_mail in sendmail 8.8

Post by Bryan Patrick Ree » Thu, 19 Feb 1998 04:00:00



>        I'm converting from an IBM RS6000 box to a Linux box for doing email
>within my department and have hit a snag. In sendmail 8.8 there are rulesets
>which prevent linux from being used as a mail relay. The vast majority of my
>users use Eudora and therefore look as though they are using the system as a
>relay.

There's a good reason for this appearance: they are using it as a relay.

Quote:>I know that I can add entries to the ip_allow file for my domain but I
>have users who do this from home through whatever ISP they have chosen which
>makes creating an ip_allow file a difficult task. Can I just comment out the
>check_mail rules and have sendmail work or is there something better that I
>can do?

Commenting out the rules should work, but that leaves your server open
to abuse.  Better would be to tell your users to use whatever mail server
their ISP tells them to use; this server is presumably willing to relay
mail for them.  If their ISP won't relay mail for dialup users, they
should go get a real ISP.

 
 
 

Partially? disabling check_mail in sendmail 8.8

Post by James E. Robinson, I » Thu, 19 Feb 1998 04:00:00



[snip snip]

Quote:> Commenting out the rules should work, but that leaves your server open
> to abuse.  Better would be to tell your users to use whatever mail server
> their ISP tells them to use; this server is presumably willing to relay
> mail for them.  If their ISP won't relay mail for dialup users, they
> should go get a real ISP.

Amen.

If your going to allow off-campus relaying, be sure you have a lot of
time to deal with spammers abusing your box.
   James

--
 James E. Robinson, III   /   Systems Programmer
 [www.four11.com] Keywords: first=james last=robinson domain=ncstate
   The Lord is my strength and song, and is become my salvation.
                                                -- Psalm 118:14

 
 
 

Partially? disabling check_mail in sendmail 8.8

Post by Duncan Simps » Sat, 21 Feb 1998 04:00:00




>[snip snip]
>> Commenting out the rules should work, but that leaves your server open
>> to abuse.  Better would be to tell your users to use whatever mail server
>> their ISP tells them to use; this server is presumably willing to relay
>> mail for them.  If their ISP won't relay mail for dialup users, they
>> should go get a real ISP.
>Amen.
>If your going to allow off-campus relaying, be sure you have a lot of
>time to deal with spammers abusing your box.
>   James

All the anti-relaying rulesets I know of allow you to list sets of IP
numbers that are allowed to relay to whoever they wish (I dynamically
get such an IP number and use mail.telstar.net to relay mail from my
flat, and it just works). Assuming your IP is not whitelisted then
using mail.telstar.net as an abuse relay emits 551 (I tested this
after implementing this feature).

Users *should* be using their ISP's mail relay---if they can not or
this is broken then they should get a real ISP (i.e. one not using
NTmail as a basic first step, because NT mail violates the internet
host requirements in various cripling ways).

If you let anyoine relay be prepared for what advanced the
anti-relaying project on mail.telstar.net (it was a long term goal
before, this moved in up to top prioirity). Not only where 3 spams
relayed in 4 days but the last spam sent over 1,000 bounces to
postmaster (multiple people, including me). I know from personal
experience that pine *really crawls* when faced with multiple-Mb 1,400
email message mail boxes.

Duncan (-:

 
 
 

1. Question on sendmail.cf for Ver8.8.8

Folks
        The environment Sparc 20 running Solaris 2.5.1 and Sendmail Ver 8.8.8.
The question I have is how can I tell sendmail through sendmail.cf to look
at the local /etc/hosts file first for any entry and not the DNS.
The entry in /etc/nsswitch.conf file looks something like this.
hosts   files dns
The ResolverOptions I have in the Sendmail.cf is as follows.
OI      +DNSRCH +DEFNAMES
The only way I can make the sendmail to look at the /etc/hosts file is by
editing the /etc/nsswitch.conf file and editing the entry for hosts to
hosts   files.
But I would be needing the dns support to. I am pretty sure there should be
some way of telling the sendmail through sendmail.cf to look at the
/etc/hosts file first and then go to the DNS.
Any suggestions or help in this regard would be appreciated. You could post

Sandeep

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