can't telnet localhost 25 on centos

Question

i have done to install and config the postfix but when i test to telnet

i get the result

Trying ::1...
telnet: connect to address ::1: Connection refused
Trying 127.0.0.1...
telnet: connect to address 127.0.0.1: Connection refused

i have try to use more way for solved the problem but can't find the solution.

the

master.cf

smtp      inet  n       -       n       -       -       smtpd
#submission inet n       -       n       -       -       smtpd
#  -o smtpd_tls_security_level=encrypt
#  -o smtpd_sasl_auth_enable=yes
#  -o smtpd_client_restrictions=permit_sasl_authenticated,reject
#  -o milter_macro_daemon_name=ORIGINATING
smtps     inet  n       -       n       -       -       smtpd
#-o smtpd_sasl_auth_enable=yes
#-o smtpd_reject_unlisted_sender=yes
#-o smtpd_recipient_restrictions=permit_sasl_authenticated,reject
#-o broken_sasl_auth_clients=yes
#  -o smtpd_tls_wrappermode=yes
#  -o smtpd_sasl_auth_enable=yes
#  -o smtpd_client_restrictions=permit_sasl_authenticated,reject
#  -o milter_macro_daemon_name=ORIGINATING
#628      inet  n       -       n       -       -       qmqpd
pickup    fifo  n       -       n       60      1       pickup
cleanup   unix  n       -       n       -       0       cleanup
qmgr      fifo  n       -       n       300     1       qmgr
#qmgr     fifo  n       -       n       300     1       oqmgr
tlsmgr    unix  -       -       n       1000?   1       tlsmgr
rewrite   unix  -       -       n       -       -       trivial-rewrite
bounce    unix  -       -       n       -       0       bounce
defer     unix  -       -       n       -       0       bounce
trace     unix  -       -       n       -       0       bounce
verify    unix  -       -       n       -       1       verify
flush     unix  n       -       n       1000?   0       flush
proxymap  unix  -       -       n       -       -       proxymap
proxywrite unix -       -       n       -       1       proxymap
smtp      unix  -       -       n       -       -       smtp
# When relaying mail as backup MX, disable fallback_relay to avoid MX loops
relay     unix  -       -       n       -       -       smtp
        -o smtp_fallback_relay=

thank you

be careful using `0.0.0.0/8` as `mynetworks`. If that server is externally accessible, you could potentially be an open relay for others to abuse. — Aaron, Feb 16 '16 at 14:46
@Aaron How would that open the server to abuse? There are no routable IP address in `0.0.0.0/8`. — kasperd, Feb 17 '16 at 16:14

score 1 · Answer 1 · answered Feb 16 '16 at 14:27

1

First, you should check that postfix process is running:

ps axu | grep master

Second, check what is listening to port 25:

netstat -apn | grep :25

You should get similiar output:

tcp        0      0 0.0.0.0:25                  0.0.0.0:*                   LISTEN      5690/master

Third, check postfix config:

postconf  | grep smtp_bind_address

It should be empty, e.g. postfix listens on all addresses:

smtp_bind_address =
smtp_bind_address6 =

Fourth, fix errors found in the steps above)

answered Feb 16 '16 at 14:27

anx

328
1
6

when i run second step then not give result just like close – Angel's Wing's Feb 16 '16 at 14:32
for the third step the step give same result – Angel's Wing's Feb 16 '16 at 14:35
It seems the postfix service is stopped. Try `/etc/init.d/postfix start` If it fails, post the output of `postfix check` – anx Feb 16 '16 at 14:38
when i use postfix check still not give result – Angel's Wing's Feb 16 '16 at 14:47
So I assume the command `/etc/init.d/postfix start` failed. Try to start it manually by hand: `postfix -vv start` and post the output. – anx Feb 16 '16 at 14:53
i have post the output in my question post – Angel's Wing's Feb 16 '16 at 14:59
Output looks good. Please, check last lines of /var/log/maillog. It should be something useful there. Also check /etc/postfix/master.cf. Post the line beginning with **smtp**. – anx Feb 16 '16 at 15:12
for the maillog no error result, and for the master.cf i have post on my question – Angel's Wing's Feb 16 '16 at 15:18
Hmm. It should work then. May be you messed up something else on the server? Let's add implicit iptables rule that permits smtp traffic: `/sbin/iptables -I INPUT -m tcp -p tcp --dport 25 -j ACCEPT ; /sbin/iptables -I OUTPUT -m tcp -p tcp --sport 25 -j ACCEPT ` – anx Feb 16 '16 at 15:22
hmm. i have done add iptables rule but connection still refused – Angel's Wing's Feb 17 '16 at 06:29

can't telnet localhost 25 on centos

1 Answers1