SMTP Failure - Could not connect to this SMTP Server

Every SMPT server on my Virtualmin installation gives this error. I’ve googled around and see that this is a fairly common problem, but I don’t know how to fix it after reading. I did read that the output of posfconf -n was helpful in solving the problem, so here it is:

[root@server ~]# postconf -n alias_database = hash:/etc/aliases alias_maps = hash:/etc/aliases allow_percent_hack = no broken_sasl_auth_clients = yes command_directory = /usr/sbin config_directory = /etc/postfix daemon_directory = /usr/libexec/postfix data_directory = /var/lib/postfix debug_peer_level = 2 home_mailbox = Maildir/ html_directory = no inet_interfaces = all inet_protocols = all mail_owner = postfix mailbox_command = /usr/bin/procmail-wrapper -o -a $DOMAIN -d $LOGNAME mailbox_size_limit = 0 mailq_path = /usr/bin/mailq.postfix manpage_directory = /usr/share/man mydestination = $myhostname, localhost.$mydomain, localhost, newaliases_path = /usr/bin/newaliases.postfix queue_directory = /var/spool/postfix readme_directory = /usr/share/doc/postfix-2.6.6/README_FILES sample_directory = /usr/share/doc/postfix-2.6.6/samples sender_bcc_maps = hash:/etc/postfix/bcc sendmail_path = /usr/sbin/sendmail.postfix setgid_group = postdrop smtpd_recipient_restrictions = permit_mynetworks permit_sasl_authenticated reject_unauth_destination smtpd_sasl_auth_enable = yes smtpd_sasl_security_options = noanonymous unknown_local_recipient_reject_code = 550 virtual_alias_maps = hash:/etc/postfix/virtual [root@server ~]#

Does the mail server name you use as smtp server resolve to your servers ip address? if not try using your ip address as smtp server in your favourite mail client.


You may also want to check your mail log for any errors… you can find that in either /var/log/maillog, or /var/log/mail.log

I’m able to connect to port 25 on your mail server, I don’t receive any kind of error when doing that – so the key is going to be either with any errors you’re seeing in the logs, or the specific settings being used in your mail client.