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<!doctype html public "-//W3C//DTD HTML 4.01 Transitional//EN"
        "http://www.w3.org/TR/html4/loose.dtd">
<html> <head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<title> Postfix manual - tlsproxy(8) </title>
</head> <body> <pre>
TLSPROXY(8)                                                        TLSPROXY(8)

<b>NAME</b>
       tlsproxy - Postfix TLS proxy

<b>SYNOPSIS</b>
       <b>tlsproxy</b> [generic Postfix daemon options]

<b>DESCRIPTION</b>
       The  <a href="tlsproxy.8.html"><b>tlsproxy</b>(8)</a>  server  implements a two-way TLS proxy. It is used by
       the <a href="postscreen.8.html"><b>postscreen</b>(8)</a> server to talk SMTP-over-TLS with remote SMTP clients
       that  are not allowlisted (including clients whose allowlist status has
       expired), and by the <a href="smtp.8.html"><b>smtp</b>(8)</a> client to support  TLS  connection  reuse,
       but it should also work for non-SMTP protocols.

       Although  one  <a href="tlsproxy.8.html"><b>tlsproxy</b>(8)</a>  process  can serve multiple sessions at the
       same time, it is a good idea  to  allow  the  number  of  processes  to
       increase with load, so that the service remains responsive.

<b>PROTOCOL EXAMPLE</b>
       The  example  below  concerns  <a href="postscreen.8.html"><b>postscreen</b>(8)</a>.  However, the <a href="tlsproxy.8.html"><b>tlsproxy</b>(8)</a>
       server is agnostic of the application protocol, and the example is eas-
       ily adapted to other applications.

       After  receiving  a  valid  remote  SMTP  client  STARTTLS command, the
       <a href="postscreen.8.html"><b>postscreen</b>(8)</a> server sends the remote SMTP client endpoint string,  the
       requested  role  (server),  and  the  requested timeout to <a href="tlsproxy.8.html"><b>tlsproxy</b>(8)</a>.
       <a href="postscreen.8.html"><b>postscreen</b>(8)</a>  then  receives  a  "TLS   available"   indication   from
       <a href="tlsproxy.8.html"><b>tlsproxy</b>(8)</a>.   If the TLS service is available, <a href="postscreen.8.html"><b>postscreen</b>(8)</a> sends the
       remote SMTP client file descriptor to <a href="tlsproxy.8.html"><b>tlsproxy</b>(8)</a>, and sends the plain-
       text 220 greeting to the remote SMTP client.  This triggers TLS negoti-
       ations between the remote SMTP client and <a href="tlsproxy.8.html"><b>tlsproxy</b>(8)</a>.  Upon completion
       of  the  TLS-level  handshake, <a href="tlsproxy.8.html"><b>tlsproxy</b>(8)</a> translates between plaintext
       from/to <a href="postscreen.8.html"><b>postscreen</b>(8)</a> and ciphertext to/from the remote SMTP client.

<b>SECURITY</b>
       The <a href="tlsproxy.8.html"><b>tlsproxy</b>(8)</a> server is moderately security-sensitive.  It  talks  to
       untrusted  clients  on  the network. The process can be run chrooted at
       fixed low privilege.

<b>DIAGNOSTICS</b>
       Problems and transactions are logged to <b>syslogd</b>(8) or <a href="postlogd.8.html"><b>postlogd</b>(8)</a>.

<b>CONFIGURATION PARAMETERS</b>
       Changes to <a href="postconf.5.html"><b>main.cf</b></a> are not picked up automatically, as <a href="tlsproxy.8.html"><b>tlsproxy</b>(8)</a> pro-
       cesses  may run for a long time depending on mail server load.  Use the
       command "<b>postfix reload</b>" to speed up a change.

       The text below provides only a parameter summary. See  <a href="postconf.5.html"><b>postconf</b>(5)</a>  for
       more details including examples.

<b>STARTTLS GLOBAL CONTROLS</b>
       The  following settings are global and therefore cannot be overruled by
       information specified in a <a href="tlsproxy.8.html"><b>tlsproxy</b>(8)</a> client request.

       <b><a href="postconf.5.html#tls_append_default_CA">tls_append_default_CA</a> (no)</b>
              Append the system-supplied default Certification Authority  cer-
              tificates   to   the   ones   specified   with  *_tls_CApath  or
              *_tls_CAfile.

       <b><a href="postconf.5.html#tls_daemon_random_bytes">tls_daemon_random_bytes</a> (32)</b>
              The number of pseudo-random bytes that an  <a href="smtp.8.html"><b>smtp</b>(8)</a>  or  <a href="smtpd.8.html"><b>smtpd</b>(8)</a>
              process  requests from the <a href="tlsmgr.8.html"><b>tlsmgr</b>(8)</a> server in order to seed its
              internal pseudo random number generator (PRNG).

       <b><a href="postconf.5.html#tls_high_cipherlist">tls_high_cipherlist</a> (see 'postconf -d' output)</b>
              The OpenSSL cipherlist for "high" grade ciphers.

       <b><a href="postconf.5.html#tls_medium_cipherlist">tls_medium_cipherlist</a> (see 'postconf -d' output)</b>
              The OpenSSL cipherlist for "medium" or higher grade ciphers.

       <b><a href="postconf.5.html#tls_low_cipherlist">tls_low_cipherlist</a> (see 'postconf -d' output)</b>
              The OpenSSL cipherlist for "low" or higher grade ciphers.

       <b><a href="postconf.5.html#tls_export_cipherlist">tls_export_cipherlist</a> (see 'postconf -d' output)</b>
              The OpenSSL cipherlist for "export" or higher grade ciphers.

       <b><a href="postconf.5.html#tls_null_cipherlist">tls_null_cipherlist</a> (eNULL:!aNULL)</b>
              The OpenSSL cipherlist for "NULL"  grade  ciphers  that  provide
              authentication without encryption.

       <b><a href="postconf.5.html#tls_eecdh_strong_curve">tls_eecdh_strong_curve</a> (prime256v1)</b>
              The  elliptic curve used by the Postfix SMTP server for sensibly
              strong ephemeral ECDH key exchange.

       <b><a href="postconf.5.html#tls_eecdh_ultra_curve">tls_eecdh_ultra_curve</a> (secp384r1)</b>
              The elliptic curve used by the Postfix SMTP server for maximally
              strong ephemeral ECDH key exchange.

       <b><a href="postconf.5.html#tls_disable_workarounds">tls_disable_workarounds</a> (see 'postconf -d' output)</b>
              List or bit-mask of OpenSSL bug work-arounds to disable.

       <b><a href="postconf.5.html#tls_preempt_cipherlist">tls_preempt_cipherlist</a> (no)</b>
              With SSLv3 and later, use the Postfix SMTP server's cipher pref-
              erence order instead of the remote  client's  cipher  preference
              order.

       Available in Postfix version 2.9 and later:

       <b><a href="postconf.5.html#tls_legacy_public_key_fingerprints">tls_legacy_public_key_fingerprints</a> (no)</b>
              A  temporary  migration  aid for sites that use certificate <i>pub-</i>
              <i>lic-key</i> fingerprints with Postfix  2.9.0..2.9.5,  which  use  an
              incorrect algorithm.

       Available in Postfix version 2.11-3.1:

       <b><a href="postconf.5.html#tls_dane_digest_agility">tls_dane_digest_agility</a> (on)</b>
              Configure <a href="https://tools.ietf.org/html/rfc7671">RFC7671</a> DANE TLSA digest algorithm agility.

       <b><a href="postconf.5.html#tls_dane_trust_anchor_digest_enable">tls_dane_trust_anchor_digest_enable</a> (yes)</b>
              Enable support for <a href="https://tools.ietf.org/html/rfc6698">RFC 6698</a> (DANE TLSA) DNS records that contain
              digests of trust-anchors with certificate usage "2".

       Available in Postfix version 2.11 and later:

       <b><a href="postconf.5.html#tlsmgr_service_name">tlsmgr_service_name</a> (tlsmgr)</b>
              The name of the <a href="tlsmgr.8.html"><b>tlsmgr</b>(8)</a> service entry in <a href="master.5.html">master.cf</a>.

       Available in Postfix version 3.0 and later:

       <b><a href="postconf.5.html#tls_session_ticket_cipher">tls_session_ticket_cipher</a> (Postfix</b> &gt;<b>= 3.0: aes-256-cbc, Postfix</b> &lt;  <b>3.0:</b>
       <b>aes-128-cbc)</b>
              Algorithm used to encrypt <a href="https://tools.ietf.org/html/rfc5077">RFC5077</a> TLS session tickets.

       <b><a href="postconf.5.html#openssl_path">openssl_path</a> (openssl)</b>
              The location of the OpenSSL command line program <b>openssl</b>(1).

       Available in Postfix version 3.2 and later:

       <b><a href="postconf.5.html#tls_eecdh_auto_curves">tls_eecdh_auto_curves</a> (see 'postconf -d' output)</b>
              The prioritized list of elliptic curves supported by the Postfix
              SMTP client and server.

       Available in Postfix version 3.4 and later:

       <b><a href="postconf.5.html#tls_server_sni_maps">tls_server_sni_maps</a> (empty)</b>
              Optional  lookup tables that map names received from remote SMTP
              clients via the TLS Server Name Indication  (SNI)  extension  to
              the appropriate keys and certificate chains.

       Available in Postfix 3.5, 3.4.6, 3.3.5, 3.2.10, 3.1.13 and later:

       <b><a href="postconf.5.html#tls_fast_shutdown_enable">tls_fast_shutdown_enable</a> (yes)</b>
              A  workaround  for implementations that hang Postfix while shut-
              ting down a TLS session, until Postfix times out.

       Available in Postfix 3.9, 3.8.1, 3.7.6, 3.6.10, 3.5.20 and later:

       <b><a href="postconf.5.html#tls_config_file">tls_config_file</a> (default)</b>
              Optional configuration file with baseline OpenSSL settings.

       <b><a href="postconf.5.html#tls_config_name">tls_config_name</a> (empty)</b>
              The application name passed by Postfix to OpenSSL  library  ini-
              tialization functions.

<b>STARTTLS SERVER CONTROLS</b>
       These settings are clones of Postfix SMTP server settings.  They  allow
       <a href="tlsproxy.8.html"><b>tlsproxy</b>(8)</a> to load the same certificate and private key information as
       the Postfix SMTP server, before dropping privileges, so  that  the  key
       files  can be kept read-only for root. These settings can currently not
       be overruled by information in a <a href="tlsproxy.8.html"><b>tlsproxy</b>(8)</a> client request,  but  that
       limitation may be removed in a future version.

       <b><a href="postconf.5.html#tlsproxy_tls_CAfile">tlsproxy_tls_CAfile</a> ($<a href="postconf.5.html#smtpd_tls_CAfile">smtpd_tls_CAfile</a>)</b>
              A  file  containing  (PEM  format)  CA  certificates of root CAs
              trusted to sign either remote SMTP client certificates or inter-
              mediate CA certificates.

       <b><a href="postconf.5.html#tlsproxy_tls_CApath">tlsproxy_tls_CApath</a> ($<a href="postconf.5.html#smtpd_tls_CApath">smtpd_tls_CApath</a>)</b>
              A  directory containing (PEM format) CA certificates of root CAs
              trusted to sign either remote SMTP client certificates or inter-
              mediate CA certificates.

       <b><a href="postconf.5.html#tlsproxy_tls_always_issue_session_ids">tlsproxy_tls_always_issue_session_ids</a>     ($<a href="postconf.5.html#smtpd_tls_always_issue_session_ids">smtpd_tls_always_issue_ses</a>-</b>
       <b><a href="postconf.5.html#smtpd_tls_always_issue_session_ids">sion_ids</a>)</b>
              Force  the Postfix <a href="tlsproxy.8.html"><b>tlsproxy</b>(8)</a> server to issue a TLS session id,
              even when TLS session caching is turned off.

       <b><a href="postconf.5.html#tlsproxy_tls_ask_ccert">tlsproxy_tls_ask_ccert</a> ($<a href="postconf.5.html#smtpd_tls_ask_ccert">smtpd_tls_ask_ccert</a>)</b>
              Ask a remote SMTP client for a client certificate.

       <b><a href="postconf.5.html#tlsproxy_tls_ccert_verifydepth">tlsproxy_tls_ccert_verifydepth</a> ($<a href="postconf.5.html#smtpd_tls_ccert_verifydepth">smtpd_tls_ccert_verifydepth</a>)</b>
              The verification depth for remote SMTP client certificates.

       <b><a href="postconf.5.html#tlsproxy_tls_cert_file">tlsproxy_tls_cert_file</a> ($<a href="postconf.5.html#smtpd_tls_cert_file">smtpd_tls_cert_file</a>)</b>
              File with the Postfix <a href="tlsproxy.8.html"><b>tlsproxy</b>(8)</a> server RSA certificate in  PEM
              format.

       <b><a href="postconf.5.html#tlsproxy_tls_ciphers">tlsproxy_tls_ciphers</a> ($<a href="postconf.5.html#smtpd_tls_ciphers">smtpd_tls_ciphers</a>)</b>
              The minimum TLS cipher grade that the Postfix <a href="tlsproxy.8.html"><b>tlsproxy</b>(8)</a> server
              will use with opportunistic TLS encryption.

       <b><a href="postconf.5.html#tlsproxy_tls_dcert_file">tlsproxy_tls_dcert_file</a> ($<a href="postconf.5.html#smtpd_tls_dcert_file">smtpd_tls_dcert_file</a>)</b>
              File with the Postfix <a href="tlsproxy.8.html"><b>tlsproxy</b>(8)</a> server DSA certificate in  PEM
              format.

       <b><a href="postconf.5.html#tlsproxy_tls_dh1024_param_file">tlsproxy_tls_dh1024_param_file</a> ($<a href="postconf.5.html#smtpd_tls_dh1024_param_file">smtpd_tls_dh1024_param_file</a>)</b>
              File  with  DH  parameters  that  the Postfix <a href="tlsproxy.8.html"><b>tlsproxy</b>(8)</a> server
              should use with non-export EDH ciphers.

       <b><a href="postconf.5.html#tlsproxy_tls_dh512_param_file">tlsproxy_tls_dh512_param_file</a> ($<a href="postconf.5.html#smtpd_tls_dh512_param_file">smtpd_tls_dh512_param_file</a>)</b>
              File with DH parameters  that  the  Postfix  <a href="tlsproxy.8.html"><b>tlsproxy</b>(8)</a>  server
              should use with export-grade EDH ciphers.

       <b><a href="postconf.5.html#tlsproxy_tls_dkey_file">tlsproxy_tls_dkey_file</a> ($<a href="postconf.5.html#smtpd_tls_dkey_file">smtpd_tls_dkey_file</a>)</b>
              File  with the Postfix <a href="tlsproxy.8.html"><b>tlsproxy</b>(8)</a> server DSA private key in PEM
              format.

       <b><a href="postconf.5.html#tlsproxy_tls_eccert_file">tlsproxy_tls_eccert_file</a> ($<a href="postconf.5.html#smtpd_tls_eccert_file">smtpd_tls_eccert_file</a>)</b>
              File with the Postfix <a href="tlsproxy.8.html"><b>tlsproxy</b>(8)</a> server  ECDSA  certificate  in
              PEM format.

       <b><a href="postconf.5.html#tlsproxy_tls_eckey_file">tlsproxy_tls_eckey_file</a> ($<a href="postconf.5.html#smtpd_tls_eckey_file">smtpd_tls_eckey_file</a>)</b>
              File  with  the  Postfix <a href="tlsproxy.8.html"><b>tlsproxy</b>(8)</a> server ECDSA private key in
              PEM format.

       <b><a href="postconf.5.html#tlsproxy_tls_eecdh_grade">tlsproxy_tls_eecdh_grade</a> ($<a href="postconf.5.html#smtpd_tls_eecdh_grade">smtpd_tls_eecdh_grade</a>)</b>
              The Postfix <a href="tlsproxy.8.html"><b>tlsproxy</b>(8)</a>  server  security  grade  for  ephemeral
              elliptic-curve Diffie-Hellman (EECDH) key exchange.

       <b><a href="postconf.5.html#tlsproxy_tls_exclude_ciphers">tlsproxy_tls_exclude_ciphers</a> ($<a href="postconf.5.html#smtpd_tls_exclude_ciphers">smtpd_tls_exclude_ciphers</a>)</b>
              List  of ciphers or cipher types to exclude from the <a href="tlsproxy.8.html"><b>tlsproxy</b>(8)</a>
              server cipher list at all TLS security levels.

       <b><a href="postconf.5.html#tlsproxy_tls_fingerprint_digest">tlsproxy_tls_fingerprint_digest</a> ($<a href="postconf.5.html#smtpd_tls_fingerprint_digest">smtpd_tls_fingerprint_digest</a>)</b>
              The  message  digest  algorithm   to   construct   remote   SMTP
              client-certificate fingerprints.

       <b><a href="postconf.5.html#tlsproxy_tls_key_file">tlsproxy_tls_key_file</a> ($<a href="postconf.5.html#smtpd_tls_key_file">smtpd_tls_key_file</a>)</b>
              File  with the Postfix <a href="tlsproxy.8.html"><b>tlsproxy</b>(8)</a> server RSA private key in PEM
              format.

       <b><a href="postconf.5.html#tlsproxy_tls_loglevel">tlsproxy_tls_loglevel</a> ($<a href="postconf.5.html#smtpd_tls_loglevel">smtpd_tls_loglevel</a>)</b>
              Enable additional Postfix  <a href="tlsproxy.8.html"><b>tlsproxy</b>(8)</a>  server  logging  of  TLS
              activity.

       <b><a href="postconf.5.html#tlsproxy_tls_mandatory_ciphers">tlsproxy_tls_mandatory_ciphers</a> ($<a href="postconf.5.html#smtpd_tls_mandatory_ciphers">smtpd_tls_mandatory_ciphers</a>)</b>
              The minimum TLS cipher grade that the Postfix <a href="tlsproxy.8.html"><b>tlsproxy</b>(8)</a> server
              will use with mandatory TLS encryption.

       <b><a href="postconf.5.html#tlsproxy_tls_mandatory_exclude_ciphers">tlsproxy_tls_mandatory_exclude_ciphers</a>               ($<a href="postconf.5.html#smtpd_tls_mandatory_exclude_ciphers">smtpd_tls_manda</a>-</b>
       <b><a href="postconf.5.html#smtpd_tls_mandatory_exclude_ciphers">tory_exclude_ciphers</a>)</b>
              Additional list of ciphers or cipher types to exclude  from  the
              <a href="tlsproxy.8.html"><b>tlsproxy</b>(8)</a> server cipher list at mandatory TLS security levels.

       <b><a href="postconf.5.html#tlsproxy_tls_mandatory_protocols">tlsproxy_tls_mandatory_protocols</a> ($<a href="postconf.5.html#smtpd_tls_mandatory_protocols">smtpd_tls_mandatory_protocols</a>)</b>
              The SSL/TLS protocols accepted by the Postfix <a href="tlsproxy.8.html"><b>tlsproxy</b>(8)</a> server
              with mandatory TLS encryption.

       <b><a href="postconf.5.html#tlsproxy_tls_protocols">tlsproxy_tls_protocols</a> ($<a href="postconf.5.html#smtpd_tls_protocols">smtpd_tls_protocols</a>)</b>
              List  of  TLS protocols that the Postfix <a href="tlsproxy.8.html"><b>tlsproxy</b>(8)</a> server will
              exclude or include with opportunistic TLS encryption.

       <b><a href="postconf.5.html#tlsproxy_tls_req_ccert">tlsproxy_tls_req_ccert</a> ($<a href="postconf.5.html#smtpd_tls_req_ccert">smtpd_tls_req_ccert</a>)</b>
              With mandatory TLS encryption, require  a  trusted  remote  SMTP
              client certificate in order to allow TLS connections to proceed.

       <b><a href="postconf.5.html#tlsproxy_tls_security_level">tlsproxy_tls_security_level</a> ($<a href="postconf.5.html#smtpd_tls_security_level">smtpd_tls_security_level</a>)</b>
              The SMTP TLS security level for the Postfix <a href="tlsproxy.8.html"><b>tlsproxy</b>(8)</a>  server;
              when a non-empty value is specified, this overrides the obsolete
              parameters <a href="postconf.5.html#smtpd_use_tls">smtpd_use_tls</a> and <a href="postconf.5.html#smtpd_enforce_tls">smtpd_enforce_tls</a>.

       <b><a href="postconf.5.html#tlsproxy_tls_chain_files">tlsproxy_tls_chain_files</a> ($<a href="postconf.5.html#smtpd_tls_chain_files">smtpd_tls_chain_files</a>)</b>
              Files with the Postfix <a href="tlsproxy.8.html"><b>tlsproxy</b>(8)</a> server keys  and  certificate
              chains in PEM format.

<b>STARTTLS CLIENT CONTROLS</b>
       These  settings are clones of Postfix SMTP client settings.  They allow
       <a href="tlsproxy.8.html"><b>tlsproxy</b>(8)</a> to load the same certificate and private key information as
       the  Postfix  SMTP  client, before dropping privileges, so that the key
       files can be kept read-only for root. Some settings may be overruled by
       information in a <a href="tlsproxy.8.html"><b>tlsproxy</b>(8)</a> client request.

       Available in Postfix version 3.4 and later:

       <b><a href="postconf.5.html#tlsproxy_client_CAfile">tlsproxy_client_CAfile</a> ($<a href="postconf.5.html#smtp_tls_CAfile">smtp_tls_CAfile</a>)</b>
              A  file  containing  CA certificates of root CAs trusted to sign
              either remote TLS server certificates or  intermediate  CA  cer-
              tificates.

       <b><a href="postconf.5.html#tlsproxy_client_CApath">tlsproxy_client_CApath</a> ($<a href="postconf.5.html#smtp_tls_CApath">smtp_tls_CApath</a>)</b>
              Directory  with  PEM format Certification Authority certificates
              that the Postfix <a href="tlsproxy.8.html"><b>tlsproxy</b>(8)</a> client uses to verify a remote  TLS
              server certificate.

       <b><a href="postconf.5.html#tlsproxy_client_chain_files">tlsproxy_client_chain_files</a> ($<a href="postconf.5.html#smtp_tls_chain_files">smtp_tls_chain_files</a>)</b>
              Files  with  the Postfix <a href="tlsproxy.8.html"><b>tlsproxy</b>(8)</a> client keys and certificate
              chains in PEM format.

       <b><a href="postconf.5.html#tlsproxy_client_cert_file">tlsproxy_client_cert_file</a> ($<a href="postconf.5.html#smtp_tls_cert_file">smtp_tls_cert_file</a>)</b>
              File with the Postfix <a href="tlsproxy.8.html"><b>tlsproxy</b>(8)</a> client RSA certificate in  PEM
              format.

       <b><a href="postconf.5.html#tlsproxy_client_key_file">tlsproxy_client_key_file</a> ($<a href="postconf.5.html#smtp_tls_key_file">smtp_tls_key_file</a>)</b>
              File  with the Postfix <a href="tlsproxy.8.html"><b>tlsproxy</b>(8)</a> client RSA private key in PEM
              format.

       <b><a href="postconf.5.html#tlsproxy_client_dcert_file">tlsproxy_client_dcert_file</a> ($<a href="postconf.5.html#smtp_tls_dcert_file">smtp_tls_dcert_file</a>)</b>
              File with the Postfix <a href="tlsproxy.8.html"><b>tlsproxy</b>(8)</a> client DSA certificate in  PEM
              format.

       <b><a href="postconf.5.html#tlsproxy_client_dkey_file">tlsproxy_client_dkey_file</a> ($<a href="postconf.5.html#smtp_tls_dkey_file">smtp_tls_dkey_file</a>)</b>
              File  with the Postfix <a href="tlsproxy.8.html"><b>tlsproxy</b>(8)</a> client DSA private key in PEM
              format.

       <b><a href="postconf.5.html#tlsproxy_client_eccert_file">tlsproxy_client_eccert_file</a> ($<a href="postconf.5.html#smtp_tls_eccert_file">smtp_tls_eccert_file</a>)</b>
              File with the Postfix <a href="tlsproxy.8.html"><b>tlsproxy</b>(8)</a> client  ECDSA  certificate  in
              PEM format.

       <b><a href="postconf.5.html#tlsproxy_client_eckey_file">tlsproxy_client_eckey_file</a> ($<a href="postconf.5.html#smtp_tls_eckey_file">smtp_tls_eckey_file</a>)</b>
              File  with  the  Postfix <a href="tlsproxy.8.html"><b>tlsproxy</b>(8)</a> client ECDSA private key in
              PEM format.

       <b><a href="postconf.5.html#tlsproxy_client_fingerprint_digest">tlsproxy_client_fingerprint_digest</a> ($<a href="postconf.5.html#smtp_tls_fingerprint_digest">smtp_tls_fingerprint_digest</a>)</b>
              The message digest algorithm used to construct remote TLS server
              certificate fingerprints.

       <b><a href="postconf.5.html#tlsproxy_client_loglevel">tlsproxy_client_loglevel</a> ($<a href="postconf.5.html#smtp_tls_loglevel">smtp_tls_loglevel</a>)</b>
              Enable  additional  Postfix  <a href="tlsproxy.8.html"><b>tlsproxy</b>(8)</a>  client  logging of TLS
              activity.

       <b><a href="postconf.5.html#tlsproxy_client_loglevel_parameter">tlsproxy_client_loglevel_parameter</a> (<a href="postconf.5.html#smtp_tls_loglevel">smtp_tls_loglevel</a>)</b>
              The    name    of    the    parameter    that    provides    the
              <a href="postconf.5.html#tlsproxy_client_loglevel">tlsproxy_client_loglevel</a> value.

       <b><a href="postconf.5.html#tlsproxy_client_scert_verifydepth">tlsproxy_client_scert_verifydepth</a> ($<a href="postconf.5.html#smtp_tls_scert_verifydepth">smtp_tls_scert_verifydepth</a>)</b>
              The verification depth for remote TLS server certificates.

       <b><a href="postconf.5.html#tlsproxy_client_use_tls">tlsproxy_client_use_tls</a> ($<a href="postconf.5.html#smtp_use_tls">smtp_use_tls</a>)</b>
              Opportunistic  mode:  use TLS when a remote server announces TLS
              support.

       <b><a href="postconf.5.html#tlsproxy_client_enforce_tls">tlsproxy_client_enforce_tls</a> ($<a href="postconf.5.html#smtp_enforce_tls">smtp_enforce_tls</a>)</b>
              Enforcement mode: require that SMTP servers use TLS  encryption.

       <b><a href="postconf.5.html#tlsproxy_client_per_site">tlsproxy_client_per_site</a> ($<a href="postconf.5.html#smtp_tls_per_site">smtp_tls_per_site</a>)</b>
              Optional  lookup  tables with the Postfix <a href="tlsproxy.8.html"><b>tlsproxy</b>(8)</a> client TLS
              usage policy by next-hop destination and by  remote  TLS  server
              hostname.

       Available in Postfix version 3.4-3.6:

       <b><a href="postconf.5.html#tlsproxy_client_level">tlsproxy_client_level</a> ($<a href="postconf.5.html#smtp_tls_security_level">smtp_tls_security_level</a>)</b>
              The  default  TLS  security  level  for  the Postfix <a href="tlsproxy.8.html"><b>tlsproxy</b>(8)</a>
              client.

       <b><a href="postconf.5.html#tlsproxy_client_policy">tlsproxy_client_policy</a> ($<a href="postconf.5.html#smtp_tls_policy_maps">smtp_tls_policy_maps</a>)</b>
              Optional lookup tables with the Postfix <a href="tlsproxy.8.html"><b>tlsproxy</b>(8)</a>  client  TLS
              security policy by next-hop destination.

       Available in Postfix version 3.7 and later:

       <b><a href="postconf.5.html#tlsproxy_client_security_level">tlsproxy_client_security_level</a> ($<a href="postconf.5.html#smtp_tls_security_level">smtp_tls_security_level</a>)</b>
              The  default  TLS  security  level  for  the Postfix <a href="tlsproxy.8.html"><b>tlsproxy</b>(8)</a>
              client.

       <b><a href="postconf.5.html#tlsproxy_client_policy_maps">tlsproxy_client_policy_maps</a> ($<a href="postconf.5.html#smtp_tls_policy_maps">smtp_tls_policy_maps</a>)</b>
              Optional lookup tables with the Postfix <a href="tlsproxy.8.html"><b>tlsproxy</b>(8)</a>  client  TLS
              security policy by next-hop destination.

<b>OBSOLETE STARTTLS SUPPORT CONTROLS</b>
       These  parameters  are supported for compatibility with <a href="smtpd.8.html"><b>smtpd</b>(8)</a> legacy
       parameters.

       <b><a href="postconf.5.html#tlsproxy_use_tls">tlsproxy_use_tls</a> ($<a href="postconf.5.html#smtpd_use_tls">smtpd_use_tls</a>)</b>
              Opportunistic TLS: announce  STARTTLS  support  to  remote  SMTP
              clients, but do not require that clients use TLS encryption.

       <b><a href="postconf.5.html#tlsproxy_enforce_tls">tlsproxy_enforce_tls</a> ($<a href="postconf.5.html#smtpd_enforce_tls">smtpd_enforce_tls</a>)</b>
              Mandatory TLS: announce STARTTLS support to remote SMTP clients,
              and require that clients use TLS encryption.

       <b><a href="postconf.5.html#tlsproxy_client_use_tls">tlsproxy_client_use_tls</a> ($<a href="postconf.5.html#smtp_use_tls">smtp_use_tls</a>)</b>
              Opportunistic mode: use TLS when a remote server  announces  TLS
              support.

       <b><a href="postconf.5.html#tlsproxy_client_enforce_tls">tlsproxy_client_enforce_tls</a> ($<a href="postconf.5.html#smtp_enforce_tls">smtp_enforce_tls</a>)</b>
              Enforcement  mode: require that SMTP servers use TLS encryption.

<b>RESOURCE CONTROLS</b>
       <b><a href="postconf.5.html#tlsproxy_watchdog_timeout">tlsproxy_watchdog_timeout</a> (10s)</b>
              How much time a <a href="tlsproxy.8.html"><b>tlsproxy</b>(8)</a> process may take to process local or
              remote I/O before it is terminated by a built-in watchdog timer.

<b>MISCELLANEOUS CONTROLS</b>
       <b><a href="postconf.5.html#config_directory">config_directory</a> (see 'postconf -d' output)</b>
              The default location of the Postfix <a href="postconf.5.html">main.cf</a> and  <a href="master.5.html">master.cf</a>  con-
              figuration files.

       <b><a href="postconf.5.html#process_id">process_id</a> (read-only)</b>
              The process ID of a Postfix command or daemon process.

       <b><a href="postconf.5.html#process_name">process_name</a> (read-only)</b>
              The process name of a Postfix command or daemon process.

       <b><a href="postconf.5.html#syslog_facility">syslog_facility</a> (mail)</b>
              The syslog facility of Postfix logging.

       <b><a href="postconf.5.html#syslog_name">syslog_name</a> (see 'postconf -d' output)</b>
              A  prefix  that  is  prepended  to  the  process  name in syslog
              records, so that, for example, "smtpd" becomes "prefix/smtpd".

       Available in Postfix 3.3 and later:

       <b><a href="postconf.5.html#service_name">service_name</a> (read-only)</b>
              The <a href="master.5.html">master.cf</a> service name of a Postfix daemon process.

<b>SEE ALSO</b>
       <a href="postscreen.8.html">postscreen(8)</a>, Postfix zombie blocker
       <a href="smtpd.8.html">smtpd(8)</a>, Postfix SMTP server
       <a href="postconf.5.html">postconf(5)</a>, configuration parameters
       <a href="postlogd.8.html">postlogd(8)</a>, Postfix logging
       syslogd(8), system logging

<b>LICENSE</b>
       The Secure Mailer license must be distributed with this software.

<b>HISTORY</b>
       This service was introduced with Postfix version 2.8.

<b>AUTHOR(S)</b>
       Wietse Venema
       IBM T.J. Watson Research
       P.O. Box 704
       Yorktown Heights, NY 10598, USA

       Wietse Venema
       Google, Inc.
       111 8th Avenue
       New York, NY 10011, USA

                                                                   TLSPROXY(8)
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