Date: Mon, 23 Aug 1999 02:13:48 +0300 From: Evren Yurtesen <yurtesen@ispro.net.tr> To: cpeters2@home.com Cc: Freebsd-Questions <freebsd-questions@FreeBSD.ORG> Subject: Re: sendmail relaying rules causing problems Message-ID: <37C0842C.CAE21FC9@ispro.net.tr> References: <000101beecf4$1fb232a0$cb730418@charles.domain>
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but then some spammer can but his domain to your machine automatically
so this is not a very good idea that they can add themselves there
automatically.
do not you think so?
here is something from sendmail documentation
relay_local_from
Allows relaying if the domain portion of the mail sender is a
local
host. This should only be used if absolutely necessary as it
opens
a window for spammers. Specifically, they can send mail to
your
mail server that claims to be from your domain (either
directly or
via a routed address), and you will go ahead and relay it out
to
arbitrary hosts on the Internet.
this lets people who has user@yourdomain.com type email address to be
able to
relay through your server. This would be a solution for you but it is
not
very safe.
and the problem is not about checking emails, they are not able to send
emails! relaying is if somebody outside of your machine is trying to
send an
email to somebody who is also outside of your machine.
Sendmail does not do anything when they are checking their emails, your
pop3
or IMAP deamon is taking care of that stuff. Just when they are sending
email
they are using sendmail.
you should see sendmail readme
http://www.sendmail.org/m4/readme.html
if you have installed contrib sources then this file also should be at
/usr/src/contrib/sendmail/cf/README
I hope this would help you
Evren
"Charles A. Peters" wrote:
>
> But what about users who may be checking mail from domains that I am
> not aware of. Sure, I can modify the relay-domains file when they
> let me know about the problem, but I would be easier if this could be
> done in an automated fashion.
>
> Thanks,
>
> Charles
>
> > -----Original Message-----
> > From: owner-freebsd-questions@FreeBSD.ORG
> > [mailto:owner-freebsd-questions@FreeBSD.ORG]On Behalf Of
> > Evren Yurtesen
> > Sent: Sunday, August 22, 1999 6:55 PM
> > To: cpeters2@home.com
> > Cc: Freebsd-Questions
> > Subject: Re: sendmail relaying rules causing problems
> >
> >
> > I believe that if you put the domains in the relay-domains file
> > everything
> > would work fine one domain per line like,
> > bellsouth.net
> > innova.net
> > carol.net
> > ...
> > then everybody who has an address like xxx.bellsouth.net or
> > yyy.innova.net
> > or zzz.carol.net will have access.
> >
> > so if you do not put their IP address you can have some kind of
> > wildcard.
> > for host names at those domain names.
> >
> > I hope the IP addresses you mention are resolved to host names. are
> > they?
> >
> > Evren
> >
> > "Charles A. Peters" wrote:
> > >
> > > I have a small email server that hosts about 200 email
> > accounts. The
> > > account holders typically check their email from
> > locations such as
> > > bellsouth.net, innova.net, carol.net, mindspring.net, etc..., but
> > > when they check from these domains, they get a relaying
> > denied error
> > > 550 message back from my server. I found that I can fix this by
> > > placing their ip address in my /etc/mail/relay-domains
> > file, but if
> > > they dial in later, I have to change the address in the
> > > /etc/mail/relay-domains file and killall -hup sendmail.
> > This is not
> > > practical.
> > >
> > > I have considered turning off the relaying rules in
> > sendmail to fix
> > > the problem, but I don't want to leave my server open for abuse.
> > >
> > > Does anyone have any suggestions as to how to fix this?
> > >
> > > Thanks in advance!
> > >
> > > Charles
> > >
> > > mailto: cpeters2@home.com
> > > mailto: charles@chickenbean.com
> > >
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> >
> >
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>
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