Nagios Support Forum

mail.log
Dec 21 08:16:27 localhost postfix/qmgr[13633]: 361FE61F: from=<[email protected]>, size=982, nrcpt=1 (queue active)
Dec 21 08:16:32 localhost postfix/smtp[461]: connect to smtp2.mailcleaner.net[2001:918:ffd1:0099]:25: Network is unreachable
Dec 21 08:16:32 localhost postfix/smtp[461]: connect to smtp.mailcleaner.net[2001:918:ffd1:0097]:25: Network is unreachable
Dec 21 08:17:02 localhost postfix/smtp[461]: connect to smtp.mailcleaner.net[195.176.194.32]:25: Connection timed out

php log
[12-21-2016 07:55:29] SMTP Error: Could not connect to SMTP host. (method=smtp;host=webmail.onshoreit.net;port=25;security=none), Referer: admin/testemail.php
[12-21-2016 07:56:12] SMTP Error: Could not connect to SMTP host. (method=smtp;host=webmail.onshoreit.net;port=25;security=none), Referer: admin/testemail.php
[12-21-2016 07:57:48] SMTP Error: Could not connect to SMTP host. (method=smtp;host=216.230.228.195;port=25;security=none), Referer: admin/testemail.php
[12-21-2016 07:58:18] Message sent! (method=sendmail), Referer: admin/testemail.php

I would like to send mail directly to my server and avoid my spam service (which has the MX records) but I can't seem to get mail out of the system at all. Postfix seems to be trying IPv6 even though I disabled v6 and the sendmail messages does not make it even though I can get to the server.

From the CLI of your Nagios XI machine, can you share the output of the following commands:
You may need to yum install nmap as well

[root@dfmco-rbunw-nagios ~]# nmap webmail.onshoreit.net -p 25,465,587

Starting Nmap 6.47 ( http://nmap.org ) at 2016-12-21 21:46 CST
Nmap scan report for webmail.onshoreit.net (216.230.228.195)
Host is up (0.0070s latency).
PORT STATE SERVICE
25/tcp filtered smtp
465/tcp open smtps
587/tcp open submission

Nmap done: 1 IP address (1 host up) scanned in 1.51 seconds
[root@dfmco-rbunw-nagios ~]# nmap smtp.mailcleaner.net -p 25,465,587

Starting Nmap 6.47 ( http://nmap.org ) at 2016-12-21 21:47 CST
Nmap scan report for smtp.mailcleaner.net (195.176.194.32)
Host is up (0.041s latency).
Other addresses for smtp.mailcleaner.net (not scanned): 193.246.63.97 193.246.63.102
rDNS record for 195.176.194.32: gate6.mailcleaner.net
PORT STATE SERVICE
25/tcp filtered smtp
465/tcp open smtps
587/tcp open submission

Nmap done: 1 IP address (1 host up) scanned in 2.07 seconds
[root@dfmco-rbunw-nagios ~]# nmap 195.176.194.32 -p 25,465,587

Starting Nmap 6.47 ( http://nmap.org ) at 2016-12-21 21:47 CST
Nmap scan report for gate6.mailcleaner.net (195.176.194.32)
Host is up (0.041s latency).
PORT STATE SERVICE
25/tcp filtered smtp
465/tcp open smtps
587/tcp open submission

Nmap done: 1 IP address (1 host up) scanned in 1.80 seconds
[root@dfmco-rbunw-nagios ~]# ping 195.176.194.32 -c 4
PING 195.176.194.32 (195.176.194.32) 56(84) bytes of data.
64 bytes from 195.176.194.32: icmp_seq=1 ttl=45 time=175 ms
64 bytes from 195.176.194.32: icmp_seq=2 ttl=45 time=171 ms
64 bytes from 195.176.194.32: icmp_seq=3 ttl=45 time=171 ms
64 bytes from 195.176.194.32: icmp_seq=4 ttl=45 time=172 ms

--- 195.176.194.32 ping statistics ---
4 packets transmitted, 4 received, 0% packet loss, time 3173ms
rtt min/avg/max/mdev = 171.641/172.712/175.235/1.464 ms

It looks like it's being filtered on both hosts on port 25, are there firewall rules in place to restrict who can send from possibly? Please run a telnet against both of them as this will help to see the response received (if any), and post the results back here.

As an example for a working server -

Figured it out! The DSL provider was blocking on their end. I put a sniffer on my firewall and was not seeing inbound packets to port 25 but the sniffer on the firewall behind the DSL was sending them.

Thanks!

Great, good to hear you got it resolved. Are we ok to lock this thread?

Yes please