4

I am trying to set up a postfix configuration where (virtual) users are allowed to only send with "From:"-addresses they own. So I put reject_authenticated_sender_login_mismatch into smtpd_sender_restrictions.

Using

query = SELECT goto FROM alias WHERE address='%s' and active=1;

in my sender_login_maps.cf I can send mails with any sender address I want, even something like madeup@not_my_domain.com.

However,

postmap -q "madeup@not_my_domain.com" mysql:/etc/postfix/sql/sender_login_maps.cf 

returns nothing as expected.

Now if I change the query to

SELECT goto FROM alias WHERE address='notinthedatabaseforsure' and active=1; 

I am not able to send any mails at all. So far so good. But the log says

postfix/smtps/smtpd[11683]: NOQUEUE: reject: RCPT from...: 553 5.7.1 <user@domain.com>: 
  Sender address rejected: not owned by user user@domain.com; from=<user@domain.com> to=<user2@domain.com> proto=ESMTP helo=<[192.168.2.103]>

even if I try to send from madeup@not_my_domain.com. user@domain.com is the login name, user2@domain.com the recipient.

In a proper setup i would expect something like

postfix/smtps/smtpd[11683]: NOQUEUE: reject: RCPT from ...: 553 5.7.1 <madeup@not_my_domain.com>: 
  Sender address rejected: not owned by user user@domain.com; from=<madeup@not_my_domain.com> to=<user2@domain.com> proto=ESMTP helo=<[192.168.2.103]>

So it looks like postfix uses the login name to search for the login name regardless of the sender address, which explains why I can send with any sender address using the query I mentioned first.

Update: I checked my sql logs and indeed, the MySQL server never sees madeup@not_my_domain.com. It only gets queries for the login address and the recipient address user2@domain.com.

Here are the smtps part from master.cf and my main.cf:

smtps inet n - - - - smtpd
  -o syslog_name=postfix/smtps
  -o smtpd_tls_wrappermode=yes
  -o tls_preempt_cipherlist=yes
  -o smtpd_tls_security_level=encrypt
  -o smtpd_sasl_auth_enable=yes
  -o smtpd_client_restrictions=permit_sasl_authenticated,reject
  -o milter_macro_daemon_name=ORIGINATING
  -o smtpd_sasl_type=dovecot
  -o smtpd_sasl_security_options=noanonymous
  -o smtpd_relay_restrictions=reject_non_fqdn_recipient,reject_unknown_recipient_domain,permit_mynetworks,permit_sasl_authenticated,reject
  -o milter_macro_daemon_name=ORIGINATING
  -o cleanup_service_name=submission-header-cleanup
mynetworks = 127.0.0.0/8
inet_interfaces = all
mydomain = domain.com
myhostname = mail.domain.com
myorigin = $mydomain
mydestination =
relayhost =


smtpd_relay_restrictions = permit_mynetworks, permit_sasl_authenticated, reject_unauth_destination, reject_non_fqdn_recipient

smtpd_recipient_restrictions =
 permit_mynetworks,
 permit_sasl_authenticated,
 reject_non_fqdn_hostname,
 reject_non_fqdn_sender,
 reject_non_fqdn_recipient,
 reject_unauth_destination,
 reject_unauth_pipelining,
 reject_invalid_hostname

smtpd_sender_restrictions =
 reject_non_fqdn_sender,
 reject_unknown_sender_domain,
 reject_unauth_pipelining,
 reject_authenticated_sender_login_mismatch,
 permit_sasl_authenticated

smtpd_helo_required = yes
smtpd_helo_restrictions =   permit_mynetworks
                            reject_invalid_helo_hostname
                            reject_non_fqdn_helo_hostname
                            reject_unknown_helo_hostname

smtpd_data_restrictions = reject_unauth_pipelining

smtpd_sasl_auth_enable = yes
smtpd_sasl_security_options = noanonymous, noplaintext
smtpd_sasl_type = dovecot
smtpd_sasl_path = private/auth

postscreen_access_list =        permit_mynetworks
                                cidr:/etc/postfix/postscreen_access
postscreen_blacklist_action = drop
postscreen_greet_action = drop

postscreen_dnsbl_threshold = 2
postscreen_dnsbl_sites = dnsbl.sorbs.net*1, bl.spamcop.net*1, ix.dnsbl.manitu.net*2, zen.spamhaus.org*2
postscreen_dnsbl_action = drop

virtual_alias_maps = mysql:/etc/postfix/sql/aliases.cf
virtual_mailbox_maps = mysql:/etc/postfix/sql/accounts.cf
virtual_mailbox_domains = mysql:/etc/postfix/sql/domains.cf
relay_domains = mysql:/etc/postfix/sql/relay_domains.cf
smtpd_sender_login_maps = mysql:/etc/postfix/sql/sender_login_maps.cf


virtual_uid_maps = static:3000
virtual_gid_maps = static:3000
virtual_mailbox_base = /home/vmail

# Disable NIS lookup warning
alias_maps=hash:/etc/aliases

append_dot_mydomain = no
recipient_delimiter = +

migrated from serverfault.com Dec 13 '16 at 9:19

This question came from our site for system and network administrators.

  • migrated upon OP's request – Sven Dec 13 '16 at 9:19
-1

If a user with a login name user@example.com may only send as user@example.com you should use reject_sender_login_mismatch before permit_sasl_authenticated

smtpd_sender_restrictions = 
    # ... skip ...
    reject_sender_login_mismatch
    permit_sasl_authenticated

This option includes functionality of both reject_authenticated_sender_login_mismatch and reject_unauthenticated_sender_login_mismatch.

Moreover, check that your SQL query for a user returns his email (AKA login) for which postfix will run tests. If it just returns 1 or other "true" value it may not work as expected.

  • My SQL query does return the login name. Using reject_sender_login_mismatch in smtpd_recipient_restrictions does not work, too. Why would I have to put it in smtpd_recipient_restriction and not smtpd_sender_restrictions, anyway? – xwst Dec 15 '16 at 17:53
  • If you use email everywhere, your login name must be an email too. – sanmai Dec 16 '16 at 0:36
  • You're right with smtpd_sender_restrictions – sanmai Dec 16 '16 at 0:36
  • As you can see in my question, my login names are email addresses and I already had reject_authenticated_sender_login_mismatch in smtpd_sender_restrictions. I tried reject_sender_login_mismatch before but without success, too. Besides, only authenticated users are allowed to send mails anyway so using one or the other should not make a difference. – xwst Dec 16 '16 at 16:01

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.