I want to run postfix + dovecot on my server. I'm doing it for first time. Postfix and Dovecot works on local - I can connect through telnet, and send/receive e-mails using commands. When I try to connect from outside, using mail client (in my case Thunderbird), I always see in client alert: Authentication failed.

My /var/log/maillog file says:

dovecot: pop3-login: Disconnected: Shutting down (auth failed, 6 attempts): user=<test.user>, method=PLAIN, rip=xxx.xxx.xxx, lip=xxx.xxx.xxx.

Distribution is CentOS 6

EDIT (postconf -n):

alias_database = hash:/etc/aliases
alias_maps = hash:/etc/aliases
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
mailq_path = /usr/bin/mailq.postfix
manpage_directory = /usr/share/man
mydestination = $myhostname, localhost.$mydomain, localhost, $mydomain
mydomain = mydomain.com
myhostname = host.mydomain.com
mynetworks = xxx.xxx.xxx/24
mynetworks_style = subnet
myorigin = $mydomain
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
sendmail_path = /usr/sbin/sendmail.postfix
setgid_group = postdrop
unknown_local_recipient_reject_code = 550

When I want to send an e-mail to outside host from Thunderbird, I get 5.7.1 <my_address@gmail.com>: Relay access denied.

Error log for this: NOQUEUE: reject: RCPT from my_vps_domain[xxx.xxx.xxx.xxx]: 554 5.7.1 <myaddress@gmail.com>: Relay access denied; from=<test.user@mydomain.com> to=<myaddress@gmail.com> proto=ESMTP helo=<[]>


You should post the contents of your 10-auth.conf and all the auth* snippet config files. There's any number of things that can be going wrong. You can start troubleshooting here:


and you can turn on debug logging with the "auth_debug" and "auth_verbose" directives.


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  • Thank you. Dovecot problem solved, but still I have problem with sending emails from mail client. Can you look at postconf in 1st post? – michail_w Apr 3 '14 at 22:38

Here the explanation for second part of your problem:

Here, postfix rejected attempt to send email via mail client with error "Relay access denied". It means thunderbird doesn't attempt to do SMTP AUTH so it doesn't permitted with configuration permit_sasl_authenticated.

Based on the output of postconf -n, you seems haven't enable SASL authentication in postfix. That's why Thunderbird doesn't authenticated himself thus caused email rejected.

You can find the tutorial about enabling SASL in postfix official docs.

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