sendmail not working for relaying messages

[Jaws]

Hi all. I am having a very aggrivating problem with sendmail...I am able to recieve messages fine, but when I want to send anything, I get this error:

550 5.7.1 <willieej2002@consolidated.net>... Relaying denied. IP name lookup failed [216.176.67.98]

my resolv.conf has the proper DNS and all, so why wont it resolve?

Please help, im very confused.

-jaws

[fjleal]

As root, edit /etc/mail/sendmail.mc and comment out the line that reads "DAEMON_OPYIONS(`Port=smtp,Addr=127.0.0.1, Name=MTA') dnl" (write "dnl" on the beginning). This line makes sendmail accept mail only from localhost. Also edit /etc/mail/access and add your subnet IPs, like "Connect: 10 RELAY" to be able to send mail from any 10.x.x.x machine, or "Connect: user@domain.com RELAY". (It is better to use IP numbers.)
Then "cd /etc/mail", "make all" (to create the database files) and restart sendmail ("/etc/init.d/sendmail reload").

Please also note: if you're trying to contact your SMTP mail server from the outside (the Internet, for the IP you mention is a public one), then you're trying to relay from a different domain, and no SMTP server should allow it!

[Jaws]

As root, edit /etc/mail/sendmail.mc and comment out the line that reads "DAEMON_OPYIONS(`Port=smtp,Addr=127.0.0.1, Name=MTA') dnl" (write "dnl" on the beginning). This line makes sendmail accept mail only from localhost. Also edit /etc/mail/access and add your subnet IPs, like "Connect: 10 RELAY" to be able to send mail from any 10.x.x.x machine, or "Connect: user@domain.com RELAY". (It is better to use IP numbers.)
Then "cd /etc/mail", "make all" (to create the database files) and restart sendmail ("/etc/init.d/sendmail reload").

Please also note: if you're trying to contact your SMTP mail server from the outside (the Internet, for the IP you mention is a public one), then you're trying to relay from a different domain, and no SMTP server should allow it!

I followed your first instructions .. and it made no difference. Can you give me an example of the access file you describe?

In my access file I have:

allprogramming.net RELAY
localhost RELAY

thanks...

-jaws

[fjleal]

Sure!
Example /etc/mail/access file:

"
localhost.localdomain RELAY
localhost RELAY
127.0.0.1 RELAY
Connect: 192.168.10 RELAY
Connect: 10 RELAY
Connect: <know-spammer-domain-name>.com REJECT
From: <known-login>@<my-domain-name>.com RELAY
To: <known-login>@<my-domain-name>.com RELAY
To: <former-worker-login>@<our-company-domain-name>.com ERROR: <former-worker-login> no longer works here!
"

Got the idea? You may use the RELAY, REJECT, DISCARD and ERROR: <msg> keywords. Please remember filtering by the "from" and/or "to" fields is not reliable, so you better use IP numbers when possible.

Hope it helps. ;)

[Jaws]

Sure!
Example /etc/mail/access file:

"
localhost.localdomain RELAY
localhost RELAY
127.0.0.1 RELAY
Connect: 192.168.10 RELAY
Connect: 10 RELAY
Connect: <know-spammer-domain-name>.com REJECT
From: <known-login>@<my-domain-name>.com RELAY
To: <known-login>@<my-domain-name>.com RELAY
To: <former-worker-login>@<our-company-domain-name>.com ERROR: <former-worker-login> no longer works here!
"

Got the idea? You may use the RELAY, REJECT, DISCARD and ERROR: <msg> keywords. Please remember filtering by the "from" and/or "to" fields is not reliable, so you better use IP numbers when possible.

Hope it helps. ;)

Hey there! Thanks for the example, it helps a bit. :-)

However, I run a public SMTP server, and since I host many people that send emails to many different places ... I dont know that restricted relay will work well! What options do I have that will still keep people from spoofing their addresses?

Thanks yet again. :)

-Jaws

[janu_sun]

Hello,

This is the contents of the /etc/mail/access file

localhost.localdomain RELAY
localhost RELAY
127.0.0.1 RELAY
192.168.x.x RELAY
Connect:192.168.10 RELAY

And still the mail server does not send email to other than @mydomain.com , any clues , as to what might be the problem?

[gavinw6662]

i would assume you have an MX record setup and what not for your domain. But in the end i had to add this line to resolve (i think) the same issue:

DAEMON_OPTIONS(`Port=smtp,Addr=127.0.0.1, Name=MTA')
DAEMON_OPTIONS(`Port=smtp,Addr=IP of your server, Name=MTA')

then remake the config file:
cd /etc/mail
make -C /etc/mail

which makes sendmail listen on the loopback, and the actual eth0 interface.