Mailgun SMTP for Postfix

Hi,

Im trying to use mailgun as SMTP for the postfix email server. So that any user email will be sent via Mailgun SMTP.

But I cannot get it working.

I followed the guide here
https://documentation.mailgun.com/en/latest/user_manual.html#smtp-relay


Some of the lines are already in the original main.cf config as default installation of CWP.
But I cannot get it working

I instantly see error SMTP Error (250): Authentication failed when I hit send.

Some config shows normal behavior. But I receive bounce email and the message is
Remote-MTA: dns; smtp.mailgun.org
Diagnostic-Code: smtp; 550 5.7.1 Relaying denied


Here is my config.

Code: [Select]

# postfix config file

# uncomment for debugging if needed
#soft_bounce=yes

# postfix main
mail_owner = postfix
setgid_group = postdrop
delay_warning_time = 4

# postfix paths
html_directory = no
command_directory = /usr/sbin
daemon_directory = /usr/libexec/postfix
queue_directory = /var/spool/postfix
sendmail_path = /usr/sbin/sendmail.postfix
newaliases_path = /usr/bin/newaliases.postfix
mailq_path = /usr/bin/mailq.postfix
manpage_directory = /usr/share/man

# network settings
inet_interfaces = all
mydomain = yourdomain.com
myhostname = "my.actualhostname.com"
mynetworks = $config_directory/mynetworks
mydestination = $myhostname =  "my.actualhostname.com"
relay_domains = proxy:mysql:/etc/postfix/mysql-relay_domains_maps.cf

# mail delivery
recipient_delimiter = +

# mappings
alias_maps = hash:/etc/aliases
alias_database = hash:/etc/aliases
transport_maps = hash:/etc/postfix/transport
#local_recipient_maps =

# virtual setup
virtual_alias_maps = proxy:mysql:/etc/postfix/mysql-virtual_alias_default_maps.cf, proxy:mysql:/etc/postfix/mysql-virtual_alias_maps.cf, regexp                                                                                              :/etc/postfix/virtual_regexp
virtual_mailbox_base = /var/vmail
virtual_mailbox_domains = proxy:mysql:/etc/postfix/mysql-virtual_domains_maps.cf
virtual_mailbox_maps = proxy:mysql:/etc/postfix/mysql-virtual_mailbox_maps.cf, proxy:mysql:/etc/postfix/mysql-virtual_alias_pipe_maps.cf
virtual_minimum_uid = 101
virtual_uid_maps = static:101
virtual_gid_maps = static:12
virtual_transport = dovecot
dovecot_destination_recipient_limit = 1

# debugging
debug_peer_level = 2
debugger_command = PATH=/bin:/usr/bin:/usr/local/bin:/usr/X11R6/bin
                 xxgdb $daemon_directory/$process_name $process_id & sleep 5

relayhost = [smtp.mailgun.org]:587
smtp_sasl_password_maps = static:mailgun@user.com:mysmtppassword

# authentication
smtp_sasl_auth_enable = yes
smtp_sasl_security_options = noanonymous
smtpd_sasl_local_domain = $myhostname =  "my.actualhostname.com"
broken_sasl_auth_clients = yes
smtpd_sasl_type = dovecot
smtpd_sasl_path = private/auth

# tls config
smtp_use_tls = yes
smtpd_use_tls = yes
smtpd_tls_security_level = may
smtpd_tls_loglevel = 1
smtpd_tls_received_header = yes
smtpd_tls_session_cache_timeout = 3600s
tls_random_source = dev:/dev/urandom
smtp_tls_session_cache_database = btree:$data_directory/smtp_tls_session_cache
# Change mail.example.com.* to your host name
smtpd_tls_key_file = /etc/pki/tls/private/hostname.key
smtpd_tls_cert_file = /etc/pki/tls/certs/hostname.bundle
smtpd_tls_CApath = /etc/ssl/certs

# rules restrictions
smtpd_client_restrictions =
smtpd_helo_restrictions =
smtpd_sender_restrictions =
smtpd_recipient_restrictions = permit_sasl_authenticated, permit_mynetworks, reject_unauth_destination, reject_non_fqdn_sender, reject_non_fqdn                                                                                              _recipient, reject_unknown_recipient_domain
# uncomment for realtime black list checks
# ,reject_rbl_client zen.spamhaus.org
# ,reject_rbl_client bl.spamcop.net
# ,reject_rbl_client dnsbl.sorbs.net
smtpd_helo_required = yes
unknown_local_recipient_reject_code = 550
disable_vrfy_command = yes
smtpd_data_restrictions = reject_unauth_pipelining

# Other options
# email size limit ~20Meg
message_size_limit = 204800000
mailbox_size_limit = 2048000000

# Vacation Scripts
vacation_destination_recipient_limit = 1
recipient_bcc_maps = proxy:mysql:/etc/postfix/mysql-virtual_vacation.cf


Who is the server provider? google cloud?

try checking if you have added only this
http://wiki.centos-webpanel.com/how-to-setup-remote-smtp-server-as-relay

don't forget that you need to add to mynetworks remote ip's

Hi All,

Thank you for your replies.

The provider was Vultr. And issue was the same with Upcloud and AWS.


Mailgun uses cyrus-sasl-plain.

By default, these are the only installed only

When you search for sasl

Code: [Select]

rpm -qa|grep sasl
cyrus-sasl-sql-2.1.26-23.el7.x86_64
cyrus-sasl-2.1.26-23.el7.x86_64
cyrus-sasl-devel-2.1.26-23.el7.x86_64
cyrus-sasl-lib-2.1.26-23.el7.x86_64

To fix

Code: [Select]

yum install cyrus-sasl-plain