Unable to send out emails using PostFix Mail Server - linux

Question

I'm unable to send email from my Linux server (3.10.0-514.10.2.el7.x86_64 #1 SMP) as root#TechX.com despite SMTP port 25 Active and Listening.
[root#TechX ~]# hostname
TechX
PostFix version is:
postconf -d | grep mail_version
mail_version = 2.10.1
milter_macro_v = $mail_name $mail_version
I checked the mail log ( /var/log/maillog ) and found the below error.
Aug 16 20:50:05 TechX postfix/pickup[25136]: AEE222A924: uid=0
from= Aug 16 20:50:05 TechX postfix/cleanup[17455]: AEE222A924:
message-id=<20170816205005.AEE222A924#email> Aug 16 20:50:05 TechX
postfix/cleanup[17455]: warning:
proxy:mysql:/etc/postfix/mysql-virtual_vacation.cf lookup error for
"root#email.TechX.com" Aug 16 20:50:05 TechX postfix/cleanup[17455]:
warning: AEE222A924: recipient_bcc_maps lookup problem Aug 16 20:50:05
TechX postfix/pickup[25136]: warning: maildrop/44677A9FE: error
writing AEE222A924: queue file write error Aug 16 20:50:06 TechX
postfix/pickup[25136]: warning: AFA982A927: message has been queued
for 80 days
I'm sharing all the ".cf" files seen in the error log.
[root#TechX ~]# more /etc/postfix/main.cf
# 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 = TechX.com
myhostname = email
mynetworks = $config_directory/mynetworks
mydestination = $myhostname, localhost.$mydomain, localhost
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_maps.cf,
regexp:/etc/postfix/virtual_regexp
virtual_alias_maps = proxy: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
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
# authentication
smtpd_sasl_auth_enable = yes
smtpd_sasl_security_options = noanonymous
smtpd_sasl_local_domain = $myhostname
broken_sasl_auth_clients = yes
smtpd_sasl_type = dovecot
smtpd_sasl_path = private/auth
# tls config
smtp_use_tls = yes
smtpd_use_tls = yes
smtpd_tls_security_level = may
smtpd_tls_loglevel = 1
smtpd_tls_received_header = yes
smtpd_tls_session_cache_timeout = 3600s
tls_random_source = dev:/dev/urandom
smtp_tls_session_cache_database =
btree:$data_directory/smtp_tls_session_cache
# Change mail.example.com.* to your host name
smtpd_tls_key_file = /etc/pki/tls/private/TechX.key
smtpd_tls_cert_file = /etc/pki/tls/certs/TechX.crt
smtp_tls_CAfile = /etc/pki/tls/certs/ca-bundle.crt
smtpd_tls_CAfile = /etc/pki/tls/certs/ca-bundle.crt
# 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_rec
ipient_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 = 9000000000
mailbox_size_limit = 2048000000
# Vacation Scripts
vacation_destination_recipient_limit = 1
recipient_bcc_maps = proxy:mysql:/etc/postfix/mysql-virtual_vacation.cf
more /etc/postfix/mysql-virtual_alias_maps.cf
hosts = localhost
user = postfix
password = xxxxxxxxxxx
dbname = postfix
query = SELECT goto FROM alias WHERE address='%s' AND (active = '1' OR active = '3')
more /etc/postfix/mysql-virtual_vacation.cf
user = postfix
password = xxxxxxxxxxx
dbname = postfix
table = vacation
select_field = email
where_field = email
additional_conditions = and active = '9'
result_format = %u#%d#autoreply.TechX
Below are my hosts file entries
more /etc/hosts
127.0.0.1 localhost localhost.localdomain localhost4
localhost4.localdomain4
::1 localhost localhost.localdomain localhost6
localhost6.localdomain6
127.0.0.1 guest
::1 guest
127.0.0.1 TechX
::1 TechX
127.0.0.1 autoreply.TechX
45.86.72.111 TechX.com
45.86.72.111 jira.TechX.com
45.86.72.111 shop.TechX.com
Can you please suggest what should i do to fix the problem ? Let me know if you need more details.

Answer 1

I had a similar problem, which was resolved by uncommenting the below line from
/etc/postfix/master.cf file...
smtps inet n - - - - smtpd
I have also tried to collate all the steps required to successfully setup a postfix server on RHEL7 configured with Gmail server.
You can quickly glance through these steps and figure out if you missed any step.
Detailed article: http://www.cubicrace.com/2017/11/unauthenticated-mail-server.html