I know this is a "generic" question, but fully CentOS related. I attempted to set up i386 v.4.1 on my primary computer at the co-located site, and thought I had everything squared away till I discovered the machine was refusing mail connections. AFIK, I had no firewall or other objects blocking port 25. It has been my experience that with most arch's and versions where sendmail is the stock mta, they always seem to work out of the box with no tweaking at all.
I have got to get this set up but will do it on a test machine rather than the production machine. Between that prblem and the changes between bind 8 and 9, I was dead in the water from the outset. Back online with the BSD machine for the time being.
Any reason why mail connections would be refused ? (yes sendmail was running too)
Thanks..
Sam
By default, sendmail only listens on 127.0.0.1
Have a look at your /etc/mail/sendmail.mc and look for this section towards the bottom:
dnl # dnl # The following causes sendmail to additionally listen to port 587 for dnl # mail from MUAs that authenticate. Roaming users who can't reach their dnl # preferred sendmail daemon due to port 25 being blocked or redirected find dnl # this useful. dnl # DAEMON_OPTIONS(`Port=submission, Name=MSA, M=Ea')dnl
Make the DAEMON_OPTIONS look like mine above, save your changes, run 'make' while in /etc/mail Then, restart sendmail.
Mike
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From: centos-bounces@centos.org [mailto:centos-bounces@centos.org] On Behalf Of Sam Drinkard Sent: Friday, November 04, 2005 3:03 PM To: CentOS@centos.org Subject: [CentOS] Sendmail I know this is a "generic" question, but fully CentOS related. I attempted to set up i386 v.4.1 on my primary computer at the co-located site, and thought I had everything squared away till I discovered the machine was refusing mail connections. AFIK, I had no firewall or other objects blocking port 25. It has been my experience that with most arch's and versions where sendmail is the stock mta, they always seem to work out of the box with no tweaking at all. I have got to get this set up but will do it on a test machine rather than the production machine. Between that prblem and the changes between bind 8 and 9, I was dead in the water from the outset. Back online with the BSD machine for the time being. Any reason why mail connections would be refused ? (yes sendmail was running too) Thanks.. Sam
Oops...my bad. Wrong section :)
dnl # dnl # The following causes sendmail to only listen on the IPv4 loopback address dnl # 127.0.0.1 and not on any other network devices. Remove the loopback dnl # address restriction to accept email from the internet or intranet. dnl # DAEMON_OPTIONS(`Port=smtp,Name=MTA')dnl
Mike
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From: centos-bounces@centos.org [mailto:centos-bounces@centos.org] On Behalf Of Sam Drinkard Sent: Friday, November 04, 2005 3:03 PM To: CentOS@centos.org Subject: [CentOS] Sendmail I know this is a "generic" question, but fully CentOS related. I attempted to set up i386 v.4.1 on my primary computer at the co-located site, and thought I had everything squared away till I discovered the machine was refusing mail connections. AFIK, I had no firewall or other objects blocking port 25. It has been my experience that with most arch's and versions where sendmail is the stock mta, they always seem to work out of the box with no tweaking at all. I have got to get this set up but will do it on a test machine rather than the production machine. Between that prblem and the changes between bind 8 and 9, I was dead in the water from the outset. Back online with the BSD machine for the time being. Any reason why mail connections would be refused ? (yes sendmail was running too) Thanks.. Sam
Mike Kercher wrote:
Oops...my bad. Wrong section :)
dnl # dnl # The following causes sendmail to only listen on the IPv4 loopback address dnl # 127.0.0.1 and not on any other network devices. Remove the loopback dnl # address restriction to accept email from the internet or intranet. dnl # DAEMON_OPTIONS(`Port=smtp,Name=MTA')dnl
Mike
From: centos-bounces@centos.org [mailto:centos-bounces@centos.org] On Behalf Of Sam Drinkard Sent: Friday, November 04, 2005 3:03 PM To: CentOS@centos.org Subject: [CentOS] Sendmail
I know this is a "generic" question, but fully CentOS related. I attempted to set up i386 v.4.1 on my primary computer at the co-located site, and thought I had everything squared away till I discovered the machine was refusing mail connections. AFIK, I had no firewall or other objects blocking port 25. It has been my experience that with most arch's and versions where sendmail is the stock mta, they always seem to work out of the box with no tweaking at all.
I have got to get this set up but will do it on a test machine rather than the production machine. Between that prblem and the changes between bind 8 and 9, I was dead in the water from the outset. Back online with the BSD machine for the time being.
Any reason why mail connections would be refused ? (yes sendmail was running too)
Thanks..
Sam
Mike,
I did that too.. because I also need the port 587 opened up due to knology blocking port 25. I'm "pretty sure" I uncommented the part about listening on 25, but will have to double check. I automatically assumed it was some type of other function blocking (refusing connects)
Thanks...
In addition to Mike's answer about editing /etc/mail/sendmail.mc, it's worthwhile mentioning netstat and lsof as general-purpose diagnostic tools:
# to discover on what tcp ports we're listening netstat -tl
# to discover to what ports sendmail is bound lsof -iTCP -n | grep sendmail
The output of these tools won't tell you how to fix the problem, but they might give you a better glimpse into the problem's nature. In this case, you'd have discovered that sendmail was only bound to the loopback interface.
Paul Heinlein wrote:
In addition to Mike's answer about editing /etc/mail/sendmail.mc, it's worthwhile mentioning netstat and lsof as general-purpose diagnostic tools:
# to discover on what tcp ports we're listening netstat -tl
# to discover to what ports sendmail is bound lsof -iTCP -n | grep sendmail
The output of these tools won't tell you how to fix the problem, but they might give you a better glimpse into the problem's nature. In this case, you'd have discovered that sendmail was only bound to the loopback interface.
Thanks for the tip Paul... will make use of it when I bring it back up.
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Mike Kercher -
Paul Heinlein -
Sam Drinkard