Ping a Specific Port

Question

E. Jaep

Asked: 2018-10-17 01:09:00 +0800 CST2018-10-17 01:09:00 +0800 CST 2018-10-17 01:09:00 +0800 CST

sender_dependant_default_transport_maps not being used by postfix

772

Intent

We are trying to use the sender_dependent_default_transport_maps feature of postfix to use different SMTP relays based on the from address of a mail. The goals are:

allow our partners to use their own domain name as from email address for automated messages (e.g. [email protected])
make sure that emails sent from [email protected] actually reach their users (e.g. [email protected])

Current configuration

Our current configuration is working fine but only uses our own SMTP server.

The /etc/postfix/master.cf is simple and looks like:

# ==========================================================================
# service type  private unpriv  chroot  wakeup  maxproc command + args
#               (yes)   (yes)   (no)    (never) (100)
# ==========================================================================
smtp      inet  n       -       y       -       -       smtpd
smtp      unix  -       -       y       -       -       smtp
relay     unix  -       -       y       -       -       smtp

The /etc/postfix/main.cf is the following:

smtpd_banner = $myhostname ESMTP $mail_name (Ubuntu)
biff = no
append_dot_mydomain = no
readme_directory = no
smtpd_tls_cert_file=<path to PEM>
smtpd_tls_key_file=<path to KEY>
smtpd_use_tls=yes
smtpd_tls_session_cache_database = btree:${data_directory}/smtpd_scache
smtp_tls_session_cache_database = btree:${data_directory}/smtp_scache
smtpd_relay_restrictions = permit_mynetworks permit_sasl_authenticated defer_unauth_destination
myhostname = appserver.provider.com
alias_maps = hash:/etc/aliases
alias_database = hash:/etc/aliases
mydestination = $myhostname, appserver, localhost.localdomain, , localhost
relayhost = mail.provider.com:465
mynetworks = 127.0.0.0/8 [::ffff:127.0.0.0]/104 [::1]/128
mailbox_size_limit = 0
recipient_delimiter = +
inet_interfaces = all
inet_protocols = all
smtp_sasl_auth_enable = yes
smtp_sasl_password_maps = hash:/etc/postfix/sasl/passwd
smtp_sasl_mechanism_filter =
smtp_sasl_security_options =
smtp_tls_security_level = encrypt
smtp_tls_wrappermode = yes
smtp_tls_mandatory_ciphers = high
canonical_maps = hash:/etc/postfix/canonical_maps
sender_canonical_maps = hash:/etc/postfix/sender_canonical_maps
header_checks = regexp:/etc/postfix/header_checks

Attempted configuration

I tried the following configuration in order to achieve the goal.

Update the main.cf:
- remove the line relayhost = mail.provider.com:465
- add a line sender_dependant_default_transport_maps = hash:/etc/postfix/sender_dependant_default_transport.map
Add a /etc/postfix/sender_dependant_default_transport.map with the following content:
```
@partner1.com     : smtp.partner1.com
@provider.com     : mail.provider.com:465
```
generate the map db: sudo postmap /etc/postfix/sender_dependant_default_transport.map
restart the service: sudo service postfix restart

Outcome

Sending from `@provider.com` to `@provider.com`

The email does not get sent:

postfix/smtpd[3011]: connect from localhost[127.0.0.1]
postfix/smtpd[3011]: 3BE61178E1E: client=localhost[127.0.0.1]
postfix/cleanup[3032]: 3BE61178E1E: message-id=<[email protected]>
postfix/qmgr[2997]: 3BE61178E1E: from=<[email protected]>, size=376, nrcpt=1 (queue active) postfix/smtp[3033]: connect to mx2.provider.com[<IPv6>]:25: Network is unreachable
postfix/smtp[3033]: SSL_connect error to mx1.provider.com[<IPv4>]:25:
postfix/smtp[3033]: warning: TLS library problem: error:140770FC:SSL routines:SSL23_GET_SERVER_HELLO:unknown protocol:s23_clnt.c:794: postfix/smtp[3033]: 3BE61178E1E: Cannot start TLS: handshake failure postfix/smtp[3033]: SSL_connect error to mx2.provider.com[<IPv4>]:25: -1 postfix/smtp[3033]: warning: TLS library problem: error:140770FC:SSL routines:SSL23_GET_SERVER_HELLO:unknown protocol:s23_clnt.c:794:
postfix/smtp[3033]: 3BE61178E1E: Cannot start TLS: handshake failure
postfix/smtp[3033]: SSL_connect error to mx3.provider.com[<IPv4>]:25:
postfix/smtp[3033]: warning: TLS library problem: error:140770FC:SSL routines:SSL23_GET_SERVER_HELLO:unknown protocol:s23_clnt.c:794: postfix/smtp[3033]: 3BE61178E1E: Cannot start TLS: handshake failure postfix/smtp[3033]: connect to mx1.provider.com[<IPv6>]:25: Network is unreachable
postfix/smtp[3033]: 3BE61178E1E: to=<[email protected]>, relay=none, delay=19, delays=18/0.01/0.54/0, dsn=4.4.1, status=deferred (connect to mx1.provider.com[<IPv6>]:25: Network is unreachable)

Sending from `@partner1.com` to `@provider.com`

The email does not get sent:

postfix/smtpd[3237]: connect from localhost[127.0.0.1]
postfix/smtpd[3237]: 6234B178E1E: client=localhost[127.0.0.1]
postfix/cleanup[3252]: 6234B178E1E: message-id=<[email protected]>
postfix/qmgr[2997]: 6234B178E1E: from=<[email protected]>, size=368, nrcpt=1 (queue active) postfix/smtp[3253]: connect to mx3.provider.com[<IPv6>]:25: Network is unreachable
postfix/smtp[3253]: SSL_connect error to mx2.provider.com[<IPv4>]:25: -1
postfix/smtp[3253]: warning: TLS library problem: error:140770FC:SSL routines:SSL23_GET_SERVER_HELLO:unknown protocol:s23_clnt.c:794: postfix/smtp[3253]: 6234B178E1E: Cannot start TLS: handshake failure postfix/smtp[3253]: connect to mx1.provider.com[<IPv6>]:25: Network is unreachable
postfix/smtp[3253]: SSL_connect error to mx3.provider.com[<IPv4>]:25: -1
postfix/smtp[3253]: warning: TLS library problem: error:140770FC:SSL routines:SSL23_GET_SERVER_HELLO:unknown protocol:s23_clnt.c:794: postfix/smtp[3253]: 6234B178E1E: Cannot start TLS: handshake failure postfix/smtp[3253]: connect to mx2.provider.com[<IPv6>]:25: Network is unreachable
postfix/smtp[3253]: 6234B178E1E: to=<[email protected]>, relay=none, delay=16, delays=16/0.01/0.33/0, dsn=4.4.1, status=deferred (connect to mx2.provider.com[<IPv6>]:25: Network is unreachable)

Actual question

Sorry for the very long introduction but I wanted to make sure I was thorough.

It seems that:

the config change in the main.cf was picked up because postfix does not try to use the default relay anymore mail.provider.com but defaults to the MX records
The sender_dependant_default_transport_maps is not used at all

How to make sure it is actually used? Could it be another cause?

According to the postfix logs while restarting, the parameter is not used:

postfix[4582]: /usr/sbin/postconf: warning: /etc/postfix/main.cf: unused parameter: sender_dependant_default_transport_maps=hash:/etc/postfix/sender_dependant_default_transport_maps

but it does tell me why it is not used..

1 Answers

Voted

E. Jaep · Answer 1 · 2018-10-17T04:22:56+08:00