Sendmail not responding on port 25

Sendmail not responding on port 25

Post by Cassidy Meye » Thu, 27 Aug 1998 04:00:00

Anyone got a bright idea why sendmail is not responding on port 25.

Sendmail not responding on port 25

Post by Neal Rhode » Sat, 29 Aug 1998 04:00:00

> Anyone got a bright idea why sendmail is not responding on port 25.

No.  But I can think of dozens of reasons mmdf won't do that, and
they all point to trying to reverse dns resolve local PC addresses.
I've gotten it work work with careful diddling of /etc/hosts, but
never understood the whole scheme.  Also there is a bug in early 5.0.2
and earlier smtpsrvr binaries that would make them mute to local pc's.
There is a patch, but I don't think it is a published supplement.


Neal Rhodes                       MNOP Ltd                     (770)-
President                Lilburn (atlanta) GA 30247             Fax:



1. port 25 not responding to outside

Hello. I'm having a very strange error regarding sendmail and outside
connections. I have it running on a gateway, and normally it's been fine
accepting mail from the outside. However, just recently (somewhere around
the last time I switched IP addresses, a day or two ago) it stopped
accepting connections from the outside. It still accepts connections from
localhost, and from other hosts on the internal LAN. It also accepts
connections from the outside on other ports like 22 (SSH) fine. But when
an outside host on the internet tries to connect to port 25 of my host, it
simply hangs and times out. I've tried opening my firewall completely,
allowing everything to smtp in /etc/hosts.allow, shutting down and
restarting sendmail completely several times, and rebooting altogether. It
still persists, and is driving me bananas.

I'm on a Slackware 9.0.0 box. Here are outputs of relevant commands and
file contents:

$ ps -ef | grep sendmail
root       144     1  0 03:43 ?        00:00:00 sendmail: accepting connections
smmsp      147     1  0 03:43 ?        00:00:00 sendmail: Queue

$ netstat -an|grep 25
tcp        0      0    *               LISTEN

sshd: ALL
smtp: ALL #I added this when the problem started, even though I know
          #sendmail isn't run from Inetd

I opened my iptables firewall completely to see if it would help:
$ iptables -L
Chain INPUT (policy ACCEPT)
target     prot opt source               destination        
ACCEPT     all  --  anywhere             anywhere          
ACCEPT     tcp  --  anywhere             anywhere           tcp dpt:ssh
ACCEPT     tcp  --  anywhere             anywhere           tcp dpt:smtp
ACCEPT     all  --  anywhere             anywhere           state

I also run Portsentry, which I tried shutting down, to no avail.

Anyway, help as to whatever (probably obvious and trivial) thing I'm
overlooking is appreciated.

Oh, and please don't reply by email until after it's fixed, as I obviously
can't receive your reply until then =o)



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