Sendmail won't deliver email if it originates from another server

dkirk · 01-31-2008, 10:05 PM

Hi there,

I've had my servers setup for years, and working well. But I've recently been making some dns and other changes (like trying to install milter), and now I've run into a strange problem.

It's a Fedora Core something server running the latest sendmail and bind.

my /etc/aliases/file contains an entry like:

editor: myemail@myisp.com

If I send an email from the problematic server eg

> echo hello | mail editor@problemserver.com

then the email gets delivered to myemail@myisp.com (as you would expect).

However, if the email comes from an external source, eg I send an email to editor@problemserver.com from my PC, then the email does not get delivered. In fact there is not even an entry recorded in /var/log/mail (nor in /var/log/*), not an error message to be found.

Does anyone have a suggestion for me to look into?

thanks

lensman3 · 02-01-2008, 07:38 PM

Take a look at the access file in "/etc/mail". I had to set mine up to look like.

Connect:localhost.localdomain RELAY
Connect:localhost RELAY
Connect:127.0.0.1 RELAY
Connect:192.168.200 RELAY
Connect:stone.bp RELAY
Connect:jow.bp RELAY
Connect:165.236.177.abc RELAY

The kicker was the last line. It is my work IP number and a fairly static IP number. I had to enter it into the file.

Sendmail.mc had the following line added.
FEATURE(`access_db',`hash -T<TMPF> -o /etc/mail/access.db')dnl

The sendmail.mc sent with Fedora is for email that originates with 127.0.0.1. When you start listening for emails on port 25, the email spammers hammer you if you relay stuff.

My email is a comcast.net and EVERYBODY blacklists comcast except for certain sites that are comcast.net approved. But that is outgoing email not incoming.

Also, your ISP could block all port 25 (smtp) packets. The only way I know to test that is from your external site do" "telnet problemserver.com 25". If you get through type "HELP" (in caps). If you don't get through your ISP or firewall is blocking port 25. Try the VRFY and EXPN commands and then look at your logs. Also try "debug"! There used to be a trapdoor back way into sendmail with root privledges years ago. Now it just writes a message to your logs.

01-31-2008, 10:05 PM	#1 (permalink)
dkirk Registered User Join Date: Jan 2008 Posts: 1 OS: linux fedora core	Sendmail won't deliver email if it originates from another server Hi there, I've had my servers setup for years, and working well. But I've recently been making some dns and other changes (like trying to install milter), and now I've run into a strange problem. It's a Fedora Core something server running the latest sendmail and bind. my /etc/aliases/file contains an entry like: editor: myemail@myisp.com If I send an email from the problematic server eg > echo hello \| mail editor@problemserver.com then the email gets delivered to myemail@myisp.com (as you would expect). However, if the email comes from an external source, eg I send an email to editor@problemserver.com from my PC, then the email does not get delivered. In fact there is not even an entry recorded in /var/log/mail (nor in /var/log/*), not an error message to be found. Does anyone have a suggestion for me to look into? thanks

02-01-2008, 07:38 PM	#2 (permalink)
lensman3 Registered User Join Date: Oct 2007 Location: Littleton, Colorado USA Posts: 470 OS: xp 64 sp2 Fedora Core 8 (vmware xp core 8 x32) Minix	Re: Sendmail won't deliver email if it originates from another server Take a look at the access file in "/etc/mail". I had to set mine up to look like. Connect:localhost.localdomain RELAY Connect:localhost RELAY Connect:127.0.0.1 RELAY Connect:192.168.200 RELAY Connect:stone.bp RELAY Connect:jow.bp RELAY Connect:165.236.177.abc RELAY The kicker was the last line. It is my work IP number and a fairly static IP number. I had to enter it into the file. Sendmail.mc had the following line added. FEATURE(`access_db',`hash -T<TMPF> -o /etc/mail/access.db')dnl The sendmail.mc sent with Fedora is for email that originates with 127.0.0.1. When you start listening for emails on port 25, the email spammers hammer you if you relay stuff. My email is a comcast.net and EVERYBODY blacklists comcast except for certain sites that are comcast.net approved. But that is outgoing email not incoming. Also, your ISP could block all port 25 (smtp) packets. The only way I know to test that is from your external site do" "telnet problemserver.com 25". If you get through type "HELP" (in caps). If you don't get through your ISP or firewall is blocking port 25. Try the VRFY and EXPN commands and then look at your logs. Also try "debug"! There used to be a trapdoor back way into sendmail with root privledges years ago. Now it just writes a message to your logs.