Hello ServerFault community,
I have a Postfix and Dovecot mail server based on MySQL, I had a problem with MySQL so I had to reinstall it and thet's where the problems started happening.
RoundCube starter randomly giving me (Just some times) IMAP server connection errors. Sometimes he says he cannot load the email because he cannot connect to IMAP and I have to reload the page to make it work again. Let's say it happens 50% of the times.
But that's not the main problem, is just something boring to use.
Today my SMTP server started making strange things. Let me explain.
My SMTP and IMAP suddently stoppend working. I could fix the IMAP by editing the NameServers of the VPS, that where causing a problem with the DNS resolving of the mail coming in. But the SMTP still works by half.
SMTP Works:
In localhost,
By doing telnet port 25 in localhost,
By doing telnet 587 also from other IPs,
With Apple's Mail Client and not PHP Mail clients. (Ports 25 and 587),
NON-PhP Mailer (I tried with www(.)gmass(.)co/smtp-test) On all the ports (25,465,587).
SMTP does not work:
With PHP Mailer (I tried with WHMCS (Main Issue) and www(.)smtper(.)net) ,WHMCS any port SMTPER works on 25,
Telnet to 465 Localhost and non,
Telnet port 25 from external hosts,
By doing telnet port 25 from external hosts (I tryed with Putty).
I am sure it is not a firewall issue at the 99.9999% as even with iPTables disabled I have the same issues. The main issue to solve is that PHPMailers does not work, like WHMCS.
My IPTables, as you can see ports are open, also because I can use them with some SMTP Clients:
Chain INPUT (policy ACCEPT)
target prot opt source destination
f2b-sshd tcp -- anywhere anywhere multiport dports 2233
ACCEPT udp -- anywhere anywhere udp dpt:465
ACCEPT tcp -- anywhere anywhere tcp dpt:urd
ACCEPT tcp -- anywhere anywhere tcp dpt:smtp
f2b-sshd tcp -- anywhere anywhere multiport dports 2233
ACCEPT tcp -- anywhere anywhere tcp dpt:pop3s
ACCEPT tcp -- anywhere anywhere tcp dpt:pop3
f2b-sshd tcp -- anywhere anywhere multiport dports 2233
ACCEPT udp -- anywhere anywhere udp dpt:11334
ACCEPT tcp -- anywhere anywhere tcp dpt:11334
ACCEPT udp -- anywhere anywhere udp dpt:19999
ACCEPT tcp -- anywhere anywhere tcp dpt:19999
ACCEPT tcp -- anywhere anywhere tcp dpt:32400
ACCEPT udp -- anywhere anywhere udp dpt:32400
ACCEPT udp -- anywhere anywhere udp dpt:8888
ACCEPT udp -- anywhere anywhere udp dpt:8096
ACCEPT tcp -- anywhere anywhere tcp dpt:8096
ACCEPT tcp -- anywhere anywhere tcp dpt:8888
ACCEPT udp -- anywhere anywhere udp dpt:50315
ACCEPT all -- anywhere anywhere
ACCEPT tcp -- anywhere anywhere tcp dpt:webmin
ACCEPT udp -- anywhere anywhere udp dpt:10000
f2b-sshd tcp -- anywhere anywhere multiport dports 2233
ACCEPT udp -- anywhere anywhere udp dpt:10040
ACCEPT udp -- anywhere anywhere udp dpt:10023
ACCEPT udp -- anywhere anywhere udp dpt:11332
ACCEPT udp -- anywhere anywhere udp dpt:mysql
ACCEPT udp -- anywhere anywhere udp dpt:110
ACCEPT udp -- anywhere anywhere udp dpt:100
ACCEPT udp -- anywhere anywhere udp dpt:domain
ACCEPT udp -- anywhere anywhere udp dpt:20
ACCEPT udp -- anywhere anywhere udp dpt:993
ACCEPT udp -- anywhere anywhere udp dpt:143
ACCEPT udp -- anywhere anywhere udp dpt:2233
ACCEPT udp -- anywhere anywhere udp dpt:465
ACCEPT udp -- anywhere anywhere udp dpt:587
ACCEPT udp -- anywhere anywhere udp dpt:1988
ACCEPT udp -- anywhere anywhere udp dpt:http-alt
ACCEPT udp -- anywhere anywhere udp dpt:22
ACCEPT udp -- anywhere anywhere udp dpt:25
ACCEPT udp -- anywhere anywhere udp dpt:80
ACCEPT udp -- anywhere anywhere udp dpt:443
ACCEPT udp -- anywhere anywhere udp dpt:2233
ACCEPT tcp -- anywhere anywhere tcp dpt:10040
ACCEPT tcp -- anywhere anywhere tcp dpt:10023
ACCEPT tcp -- anywhere anywhere tcp dpt:11332
ACCEPT tcp -- anywhere anywhere tcp dpt:mysql
ACCEPT tcp -- anywhere anywhere tcp dpt:pop3
ACCEPT tcp -- anywhere anywhere tcp dpt:100
ACCEPT tcp -- anywhere anywhere tcp dpt:domain
ACCEPT tcp -- anywhere anywhere tcp dpt:ftp-data
ACCEPT tcp -- anywhere anywhere tcp dpt:imaps
ACCEPT tcp -- anywhere anywhere tcp dpt:imap2
ACCEPT tcp -- anywhere anywhere tcp dpt:2233
ACCEPT tcp -- anywhere anywhere tcp dpt:urd
ACCEPT tcp -- anywhere anywhere tcp dpt:submission
ACCEPT tcp -- anywhere anywhere tcp dpt:1988
ACCEPT tcp -- anywhere anywhere tcp dpt:http-alt
ACCEPT tcp -- anywhere anywhere tcp dpt:ssh
ACCEPT tcp -- anywhere anywhere tcp dpt:smtp
ACCEPT tcp -- anywhere anywhere tcp dpt:http
ACCEPT tcp -- anywhere anywhere tcp dpt:https
ACCEPT tcp -- anywhere anywhere tcp dpt:2233
ACCEPT all -- anywhere anywhere state RELATED,ESTABLISHED
DROP all -- anywhere anywhere
Chain FORWARD (policy ACCEPT)
target prot opt source destination
ACCEPT all -- anywhere anywhere
ACCEPT all -- anywhere anywhere
Chain OUTPUT (policy ACCEPT)
target prot opt source destination
ACCEPT all -- anywhere anywhere state RELATED,ESTABLISHED
Chain f2b-sshd (4 references)
target prot opt source destination
RETURN all -- anywhere anywhere
RETURN all -- anywhere anywhere
RETURN all -- anywhere anywhere
RETURN all -- anywhere anywhere
Thank you for any help you may give me. Bye!
PS: Before the MySQL Edit some weeks ago everything was working fine even with the PHP Based Mail clients but I don't know if it is a problem of the Mail Host or the PHP Host (WHMCS and SMTPER) as with some website and SMTP clients everything works fine. e.g. Apple's Email.
Edit: I also have Postfix spam in console:
Oct 30 11:06:07 mail.indst.eu systemd[1]: Starting Postfix Mail Transport Agent...
Oct 30 11:06:07 mail.indst.eu systemd[1]: Started Postfix Mail Transport Agent.
Oct 30 11:06:07 mail.indst.eu systemd[1]: Reloading Postfix Mail Transport Agent.
Oct 30 11:06:07 mail.indst.eu systemd[1]: Reloaded Postfix Mail Transport Agent.
Oct 30 11:06:07 mail.indst.eu systemd[1]: Reloading Postfix Mail Transport Agent.
Oct 30 11:06:07 mail.indst.eu systemd[1]: Reloaded Postfix Mail Transport Agent.
