Hello,
I have a single postfix server servicing my company’s domain and several
customer domains. All outbound mail is first received by postfix, then sent to
the same barracuda email service to go on to it’s final destination.
I want Postfix to use a specific local IPv4 address when it connects to the
barracuda relay, depending on which domain the email is from. This will
ultimately show up in the email headers for the recipient, and I need to
separate my company from the customers.
If the mail is from mycompany.com , use local IP address (eth0) 10.50.55.16
when connecting to the barracuda service to send the mail.
All other domains (our customers), use 10.50.55.17 (eth0:1)
These local IPs ultimately NAT to different public IPv4 on different subnets
and different reverse DNS names, etc.
I have already configured postfix to listen on both IP address, and even to use
different TLS certificates for them via the master.cf and I verified this is
working. But even connecting to the second IP via SMTP, authenticating and
sending a mail, the first IP is used when connecting to the relay host, as
seen in the headers of the email.
My configuration is slightly broken right now, but I don’t know how to proceed
to accomplish what I am trying to do.
Thanks for any help,
- Kevin
my /etc/postfix/transport (I know this isn’t working .. )
mycompany.com smtp:[10.50.55.16]:587
customer1.com smtp:[10.50.55.17]:587
customer2.com smtp:[10.50.55.17]:587
postconfig -nf:
postconf: warning: /etc/postfix/main.cf: unused parameter:
sender_based_routing=yes
alias_maps =
append_dot_mydomain = no
broken_sasl_auth_clients = yes
config_directory = /etc/postfix
disable_vrfy_command = yes
inet_protocols = ipv4
local_transport = error:Local Transport Disabled
mydestination = localhost.$mydomain localhost
mydomain = mailsystem.com
myhostname = mailsystem.com
mynetworks = 127.0.0.0/8
postscreen_greet_action = enforce
smtpd_banner = $myhostname ESMTP $mail_name (Ubuntu)
smtpd_client_new_tls_session_rate_limit = 10
smtpd_client_restrictions = check_client_access cidr:/etc/postfix/drop.cidr
smtpd_data_restrictions = reject_multi_recipient_bounce
smtpd_delay_reject = no
smtpd_helo_required = yes
smtpd_helo_restrictions = permit_mynetworks check_helo_access
pcre:/etc/postfix/identitycheck.pcre reject_invalid_hostname
smtpd_recipient_restrictions = reject_non_fqdn_recipient
reject_unknown_recipient_domain permit_sasl_authenticated permit_mynetworks
reject_unauth_destination check_sender_ns_access cidr:/etc/postfix/drop.cidr
check_sender_mx_access cidr:/etc/postfix/drop.cidr reject_rbl_client
ix.dnsbl.manitu.net permit
smtpd_sasl_auth_enable = yes
smtpd_sasl_path = private/auth
smtpd_sasl_type = dovecot
smtpd_sender_restrictions = reject_non_fqdn_sender reject_unknown_sender_domain
smtpd_tls_dh1024_param_file = ${config_directory}/certs/dh_1024.pem
smtpd_tls_dh512_param_file = ${config_directory}/certs/dh_512.pem
smtpd_tls_exclude_ciphers = EXP EDH-RSA-DES-CBC-SHA ADH-DES-CBC-SHA DES-CBC-SHA
SEED-SHA
smtpd_tls_loglevel = 2
smtpd_tls_session_cache_database = btree:/etc/postfix/smtpd_session_cache
tls_random_source = dev:/dev/urandom
transport_maps = hash:/etc/postfix/transport
virtual_alias_maps = proxy:ldap:/etc/postfix/ldap_virtual_aliases.cf
virtual_mailbox_domains = hash:/etc/postfix/virtual_domains
virtual_mailbox_maps = proxy:ldap:/etc/postfix/ldap_virtual_recipients.cf
hash:/etc/postfix/transport
virtual_transport = dovecot
postconf -Mf:
dovecot unix - n n - - pipe flags=ODRhu
user=vmail:vmail argv=/usr/lib/dovecot/deliver -e -f ${sender} -d
${recipient}
10.50.55.16- unix - n n - - smtp
-o smtp_bind_address=10.50.55.16
-o smtp_bind_address6=
-o smtp_address_preference=ipv4
10.50.55.17- unix - n n - - smtp
-o smtp_bind_address=10.50.55.17
-o smtp_bind_address6=
-o smtp_address_preference=ipv4
10.50.55.16:smtp inet n - n - - smtpd
-o smtpd_tls_cert_file=/etc/ssl/certs/mail.mycompany.com-chain.crt
-o smtpd_tls_key_file=/etc/ssl/private/mail.mycompany.com.key
10.50.55.16:smtps inet n - n - - smtpd
-o smtpd_tls_wrappermode=yes
-o smtpd_tls_cert_file=/etc/ssl/certs/mail.mycompany.com-chain.crt
-o smtpd_tls_key_file=/etc/ssl/private/mail.mycompany.com.key
10.50.55.16:submission inet n - n - - smtpd
-o smtpd_enforce_tls=yes
-o smtpd_tls_security_level=encrypt
-o smtpd_sasl_auth_enable=yes
-o smtpd_client_restrictions=permit_sasl_authenticated,reject
-o smtpd_sender_restrictions=
-o smtpd_tls_cert_file=/etc/postfix/cert1.pem
-o smtpd_tls_key_file=/etc/postfix/cert1.pem
10.50.55.17:smtp inet n - n - - smtpd
-o
smtpd_tls_cert_file=/etc/letsencrypt/live/mail.customerservers.com/fullchain.pem
-o
smtpd_tls_key_file=/etc/letsencrypt/live/mail.customerservers.com/privkey.pem
10.50.55.17:smtps inet n - n - - smtpd
-o smtpd_tls_wrappermode=yes
-o
smtpd_tls_cert_file=/etc/letsencrypt/live/mail.customerservers.com/fullchain.pem
-o
smtpd_tls_key_file=/etc/letsencrypt/live/mail.customerservers.com/privkey.pem
10.50.55.17:submission inet n - n - - smtpd
-o smtpd_enforce_tls=yes
-o smtpd_tls_security_level=encrypt
-o smtpd_sasl_auth_enable=yes
-o smtpd_client_restrictions=permit_sasl_authenticated,reject
-o smtpd_sender_restrictions=
-o smtpd_tls_cert_file=/etc/postfix/cert2.pem
-o smtpd_tls_key_file=/etc/postfix/cert2.pem
pickup unix n - - 60 1 pickup
cleanup unix n - - - 0 cleanup
qmgr unix n - n 300 1 qmgr
tlsmgr unix - - - 1000? 1 tlsmgr
rewrite unix - - - - - trivial-rewrite
bounce unix - - - - 0 bounce
defer unix - - - - 0 bounce
trace unix - - - - 0 bounce
verify unix - - - - 1 verify
flush unix n - - 1000? 0 flush
proxymap unix - - n - - proxymap
proxywrite unix - - n - 1 proxymap
smtp unix - - - - - smtp
relay unix - - - - - smtp
showq unix n - - - - showq
error unix - - - - - error
retry unix - - - - - error
discard unix - - - - - discard
local unix - n n - - local
virtual unix - n n - - virtual
lmtp unix - - - - - lmtp
anvil unix - - - - 1 anvil
scache unix - - - - 1 scache
maildrop unix - n n - - pipe flags=DRhu
user=vmail argv=/usr/bin/maildrop -d ${recipient}
uucp unix - n n - - pipe flags=Fqhu
user=uucp argv=uux -r -n -z -a$sender - $nexthop!rmail ($recipient)
ifmail unix - n n - - pipe flags=F user=ftn
argv=/usr/lib/ifmail/ifmail -r $nexthop ($recipient)
bsmtp unix - n n - - pipe flags=Fq.
user=bsmtp argv=/usr/lib/bsmtp/bsmtp -t$nexthop -f$sender $recipient
scalemail-backend unix - n n - 2 pipe flags=R
user=scalemail argv=/usr/lib/scalemail/bin/scalemail-store ${nexthop}
${user} ${extension}
mailman unix - n n - - pipe flags=FR
user=list argv=/usr/lib/mailman/bin/postfix-to-mailman.py ${nexthop}
${user}
