search for: smtp_host_lookup

...quot;warning: relayhost configuration problem" This computer is set up to relay outbound email via postfix to another computer on my network by name, whose name and IP address is specified in the /etc/hosts file. A bit of reading told me that I have to add this line to /etc/postfix/main.cf: smtp_host_lookup = dns,native Without that line, postfix won't check /etc/hosts to look up an IP address. Oddly, this setup has been working for several months WITHOUT that line in main.cf and it just stopped working when the latest kernel was installed. According to the documentation http://www.postfix.org/...

On 04/27/2016 12:30 AM, James Hogarth wrote: *snip* > > Unless you have a very specific requirement for a very bleeding edge > feature it's fundamentally a terrible idea to move away from the > distribution packages in something as exposed as a webserver ... I use to believe that. However I no longer. First of all, advancements in TLS happen too quickly. The RHEL philosophy of

...DNS query and if I have a DANE record, then they can require that that the TLS connection they make to my SMTP server uses a certificate with a fingerprint that matches. That is the only reliable way to avoid MITM with SMTP. It's easy to set up in postfix - smtp_dns_support_level = dnssec smtp_host_lookup = dns But with the postfix that comes with CentOS 7 - it is too old for that, so Postfix with CentOS 7 will never even try to verify the TLS certificate of the servers it connects to. It's a stale version of postfix and people running postfix on CentOS 7 should use a newer version.

...th = /usr/bin/newaliases.postfix queue_directory = /var/spool/postfix readme_directory = /usr/share/doc/postfix-2.3.3/README_FILES sample_directory = /usr/share/doc/postfix-2.3.3/samples sendmail_path = /usr/sbin/sendmail.postfix setgid_group = postdrop smtp_generic_maps = hash:/etc/postfix/generic smtp_host_lookup = native,dns smtp_tls_note_starttls_offer = yes smtp_use_tls = yes smtpd_banner = $myhostname Microsoft ESMTP MAIL Service ready (NOT WINDOWS JUST A DECOY) smtpd_helo_required = yes smtpd_recipient_restrictions = permit_mynetworks, permit_sasl_authenticated, reject_unauth_destination smtpd_sasl_a...

...en they can require that > that the TLS connection they make to my SMTP server uses a certificate > with a fingerprint that matches. > > That is the only reliable way to avoid MITM with SMTP. > > It's easy to set up in postfix - > > smtp_dns_support_level = dnssec > smtp_host_lookup = dns > Sounds good, but how many domain MX servers have set up these fingerprint keys - 1%, maybe 2%, so how do you code for that? I guess I'm thinking it uses it if available. So even if you do post it on your DNS, how many clients out there are using DANE on their set up? By the time...

...ation_concurrency_limit smtp_destination_recipient_limit = $default_destination_recipient_limit smtp_discard_ehlo_keyword_address_maps = smtp_discard_ehlo_keywords = smtp_enforce_tls = no smtp_fallback_relay = $fallback_relay smtp_generic_maps = smtp_helo_name = $myhostname smtp_helo_timeout = 300s smtp_host_lookup = dns smtp_line_length_limit = 0 smtp_mail_timeout = 300s smtp_mx_address_limit = 5 smtp_mx_session_limit = 2 smtp_never_send_ehlo = no smtp_pix_workaround_delay_time = 10s smtp_pix_workaround_threshold_time = 500s smtp_quit_timeout = 300s smtp_quote_rfc821_envelope = yes smtp_randomize_addresses =...

...= 120s smtp_data_xfer_timeout = 180s smtp_defer_if_no_mx_address_found = no smtp_destination_concurrency_limit = $default_destination_concurrency_limit smtp_destination_recipient_limit = $default_destination_recipient_limit smtp_enforce_tls = no smtp_helo_name = $myhostname smtp_helo_timeout = 300s smtp_host_lookup = dns smtp_line_length_limit = 990 smtp_mail_timeout = 300s smtp_mx_address_limit = 0 smtp_mx_session_limit = 2 smtp_never_send_ehlo = no smtp_pix_workaround_delay_time = 10s smtp_pix_workaround_threshold_time = 500s smtp_quit_timeout = 300s smtp_quote_rfc821_envelope = yes smtp_randomize_addresses...

HI, > You could set > > syslog_facility = local5 > > and have all the log messages in the messages file. According to the output of command # doveadm log find every type of message goes to the file I was looking at, "/var/spool/maillog". >> So, is it postfix doing the local mail delivery, not dovecot? >> > To answer this question please post relevant

...ehlo_keyword_address_maps = smtp_discard_ehlo_keywords = smtp_dns_resolver_options = smtp_enforce_tls = no smtp_extra_recipient_limit = $default_extra_recipient_limit smtp_fallback_relay = $fallback_relay smtp_generic_maps = smtp_header_checks = smtp_helo_name = $myhostname smtp_helo_timeout = 300s smtp_host_lookup = dns smtp_initial_destination_concurrency = $initial_destination_concurrency smtp_line_length_limit = 998 smtp_mail_timeout = 300s smtp_mime_header_checks = smtp_minimum_delivery_slots = $default_minimum_delivery_slots smtp_mx_address_limit = 5 smtp_mx_session_limit = 2 smtp_nested_header_checks =...

...= smtp_discard_ehlo_keywords = smtp_dns_resolver_options = smtp_dns_support_level = smtp_enforce_tls = no smtp_extra_recipient_limit = $default_extra_recipient_limit smtp_fallback_relay = $fallback_relay smtp_generic_maps = smtp_header_checks = smtp_helo_name = $myhostname smtp_helo_timeout = 300s smtp_host_lookup = dns smtp_initial_destination_concurrency = $initial_destination_concurrency smtp_line_length_limit = 998 smtp_mail_timeout = 300s smtp_mime_header_checks = smtp_minimum_delivery_slots = $default_minimum_delivery_slots smtp_mx_address_limit = 5 smtp_mx_session_limit = 2 smtp_nested_header_checks =...

...ehlo_keyword_address_maps = smtp_discard_ehlo_keywords = smtp_dns_resolver_options = smtp_enforce_tls = no smtp_extra_recipient_limit = $default_extra_recipient_limit smtp_fallback_relay = $fallback_relay smtp_generic_maps = smtp_header_checks = smtp_helo_name = $myhostname smtp_helo_timeout = 300s smtp_host_lookup = dns smtp_initial_destination_concurrency = $initial_destination_concurrency smtp_line_length_limit = 998 smtp_mail_timeout = 300s smtp_mime_header_checks = smtp_minimum_delivery_slots = $default_minimum_delivery_slots smtp_mx_address_limit = 5 smtp_mx_session_limit = 2 smtp_nested_header_checks =...