Difference between revisions of "Postfix"
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== Securing incoming and outgoing mail == | == Securing incoming and outgoing mail == | ||
+ | {{TLS note|poodle=Since mid-2015, the default settings have been safe against [http://disablessl3.com/ POODLE].}} | ||
For more information, see [http://www.postfix.org/TLS_README.html Postfix TLS Support]. | For more information, see [http://www.postfix.org/TLS_README.html Postfix TLS Support]. | ||
Line 146: | Line 147: | ||
=== Secure SMTP (receiving) === | === Secure SMTP (receiving) === | ||
− | By default, Postfix will not accept secure mail. | + | By default, Postfix will not accept secure mail. |
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
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− | |||
To enable STARTTLS over SMTP (port 587, the proper way of securing SMTP), add the following lines to {{ic|main.cf}} | To enable STARTTLS over SMTP (port 587, the proper way of securing SMTP), add the following lines to {{ic|main.cf}} | ||
Line 601: | Line 592: | ||
Full documentation is found [http://www.postfix.org/TLS_README.html#client_tls_dane here]. | Full documentation is found [http://www.postfix.org/TLS_README.html#client_tls_dane here]. | ||
+ | |||
+ | === Sender Policy Framework === | ||
+ | |||
+ | To use the [[Sender Policy Framework]] with Postfix, [[install]] {{AUR|python-postfix-policyd-spf}}. | ||
+ | |||
+ | Edit {{ic|/etc/python-policyd-spf/policyd-spf.conf}} to your needs. An extensively commented version can be found at {{ic|/etc/python-policyd-spf/policyd-spf.conf.commented}}. | ||
+ | Pay some extra attention to the HELO check policy, as standard settings strictly reject HELO failures. | ||
+ | |||
+ | In the main.cf add a timeout for the policyd: | ||
+ | |||
+ | {{hc|/etc/postfix/main.cf|2= | ||
+ | policy-spf_time_limit = 3600s | ||
+ | }} | ||
+ | |||
+ | Then add a transport | ||
+ | |||
+ | {{hc|/etc/postfix/master.cf|2= | ||
+ | policy-spf unix - n n - 0 spawn | ||
+ | user=nobody argv=/usr/bin/policyd-spf | ||
+ | }} | ||
+ | |||
+ | Lastly you need to add the policyd to the {{ic|smtpd_recipient_restrictions}}. To minimize load put it to the end of the restrictions: | ||
+ | |||
+ | {{hc|/etc/postfix/main.cf|2= | ||
+ | smtpd_recipient_restrictions= | ||
+ | ... | ||
+ | permit_sasl_authenticated | ||
+ | permit_mynetworks | ||
+ | reject_unauth_destination | ||
+ | check_policy_service unix:private/policy-spf | ||
+ | }} | ||
+ | |||
+ | You can test your Setup with the following: | ||
+ | |||
+ | {{hc|/etc/python-policyd-spf/policyd-spf.conf|2= | ||
+ | defaultSeedOnly = 0 | ||
+ | }} | ||
+ | |||
+ | === Sender Rewriting Scheme === | ||
+ | |||
+ | To use the [[Sender Rewriting Scheme]] with Postfix, [[install]] {{AUR|postsrsd}} and adjust the settings: | ||
+ | |||
+ | {{hc|/etc/postsrsd/postsrsd|2= | ||
+ | SRS_DOMAIN=yourdomain.tld | ||
+ | SRS_EXCLUDE_DOMAINS=yourotherdomain.tld,yet.anotherdomain.tld | ||
+ | SRS_SEPARATOR== | ||
+ | SRS_SECRET=/etc/postsrsd/postsrsd.secret | ||
+ | SRS_FORWARD_PORT=10001 | ||
+ | SRS_REVERSE_PORT=10002 | ||
+ | RUN_AS=postsrsd | ||
+ | CHROOT=/usr/lib/postsrsd | ||
+ | }} | ||
+ | |||
+ | Enable and start the daemon, making sure it runs after reboot as well. | ||
+ | Then configure postfix accordingly by tweaking the following lines: | ||
+ | |||
+ | {{hc|/etc/postfix/main.cf|2= | ||
+ | sender_canonical_maps = tcp:localhost:10001 | ||
+ | sender_canonical_classes = envelope_sender | ||
+ | recipient_canonical_maps = tcp:localhost:10002 | ||
+ | recipient_canonical_classes= envelope_recipient,header_recipient | ||
+ | }} | ||
+ | |||
+ | Restart postfix and start forwarding mail. | ||
== See also == | == See also == |
Revision as of 09:18, 6 July 2018
From Postfix's site:
- Postfix attempts to be fast, easy to administer, and secure, while at the same time being sendmail compatible enough to not upset existing users. Thus, the outside has a sendmail-ish flavor, but the inside is completely different.
The goal of this article is to setup Postfix and explain what the basic configuration files do. There are instructions for setting up local system user-only delivery and a link to a guide for virtual user delivery.
Contents
- 1 Installation
- 2 Configuration
- 3 Start Postfix
- 4 Securing incoming and outgoing mail
- 5 Extra
- 6 See also
Installation
Configuration
master.cf
/etc/postfix/master.cf
is the master configuration file where you can specify which protocols will be served. It is also the place where you can put your new pipes e.g. to check for Spam!
It is recommended to enable secure SMTP as described in #Secure SMTP (sending) and #Secure SMTP (receiving).
See this page for more information about encrypting outgoing and incoming email.
main.cf
/etc/postfix/main.cf
is the main configuration file where everything is configured. The settings below are recommended for virtual local-only delivery.
myhostname
should be set if your mail server has multiple domains, and you do not want the primary domain to be the mail host. You should have both a DNS A record and an MX record point to this hostname.
myhostname = mail.nospam.net
mydomain
is usually the value ofmyhostname
, minus the first part. If your domain is wonky, then just set it manually.
mydomain = nospam.net
myorigin
is where the email will be seen as being sent from. I usually set this to the value ofmydomain
. For simple servers, this works fine. This is for mail originating from a local account. Since we are not doing local delivery (except sending), then this is not really as important as it normally would be.
myorigin = $mydomain
mydestination
is the lookup for local users.
mydestination = $myhostname, localhost.$mydomain, localhost, $mydomain
mynetworks
andmynetworks_style
control relaying, and whom is allowed to. We do not want any relaying.
- For our sakes, we will simply set
mynetwork_style
to host, as we are trying to make a standalone Postfix host, that people will use webmail on. No relaying, no other MTA's. Just webmail. mynetworks_style = host
relaydomains
controls the destinations that Postfix will relay TO. The default value is empty. This should be fine for now.
relay_domains =
home_mailbox
ormail_spool_directory
control how mail is delivered/stored for the users.
- If set,
mail_spool_directory
specifies an absolute path where mail gets delivered. By default Postfix stores mails in/var/spool/mail
.
mail_spool_directory = /home/vmailer
- Alternatively, if set,
home_mailbox
specifies a mailbox relative to the user's home directory where mail gets delivered (eg: /home/vmailer).
- Courier-IMAP requires "Maildir" format, so you must set it like the following example with trailing slash:
home_mailbox = Maildir/
Default message and mailbox size limits
Postfix imposes both message and mailbox size limits by default. The message_size_limit controls the maximum size in bytes of a message, including envelope information. (default 10240000) The mailbox_size_limit controls the maximum size of any local individual mailbox or maildir file. This limits the size of any file that is written to upon local delivery, including files written by external commands (i.e. procmail) that are executed by the local delivery agent. (default is 51200000, set to 0 for no limit) If bounced message notifications are generated, check the size of the local mailbox under /var/spool/mail
and use postconf to check these size limits:
# postconf mailbox_size_limit mailbox_size_limit = 51200000 # postconf message_size_limit message_size_limit = 10240000
Aliases
You can specify aliases (also known as forwarders) in /etc/postfix/aliases
.
You need to map all mail addressed to root to another account since it is not a good idea to read mail as root.
Uncomment the following line, and change you
to a real account.
root: you
Once you have finished editing /etc/postfix/aliases
you must run the postalias command:
postalias /etc/postfix/aliases
For later changes you can use:
newaliases
~/.forward
, e.g. /root/.forward
for root. Specify the user to whom root mail should be forwarded, e.g. user@localhost.
/root/.forward
user@localhost
Local mail
To only deliver mail to local system users (that are in /etc/passwd
) update /etc/postfix/main.cf
to reflect the following configuration. Uncomment, change, or add the following lines:
myhostname = localhost mydomain = localdomain mydestination = $myhostname, localhost.$mydomain, localhost inet_interfaces = $myhostname, localhost mynetworks_style = host default_transport = error: outside mail is not deliverable
All other settings may remain unchanged. After setting up the above configuration file, you may wish to set up some #Aliases and then #Start Postfix.
Virtual mail
Virtual mail is mail that does not map to a user account (/etc/passwd
).
See Virtual user mail system for a comprehensive guide how to set it up.
DNS records
Check configuration
Run the postfix check
command. It should output anything that you might have done wrong in a config file.
To see all of your configs, type postconf
. To see how you differ from the defaults, try postconf -n
.
Start Postfix
newaliases
at least once for postfix to run, even if you did not set up any #Aliases.Start/enable the postfix.service
.
Securing incoming and outgoing mail
For more information, see Postfix TLS Support.
Secure SMTP (sending)
By default, Postfix/sendmail will not send email encrypted to other SMTP servers. To use TLS when available, add the following line to main.cf
:
/etc/postfix/main.cf
smtp_tls_security_level = may
To enforce TLS (and fail when the remote server does not support it), change may
to encrypt
. Note, however, that this violates RFC 2487 if the SMTP server is publicly referenced.
Secure SMTP (receiving)
By default, Postfix will not accept secure mail.
To enable STARTTLS over SMTP (port 587, the proper way of securing SMTP), add the following lines to main.cf
/etc/postfix/main.cf
smtpd_tls_security_level = may smtpd_tls_cert_file = /path/to/cert.pem smtpd_tls_key_file = /path/to/key.pem
In master.cf
, find and remove the comment from the following line to enable the service on that port:
/etc/postfix/master.cf
submission inet n - n - - smtpd
If you need support for the deprecated SMTPS port 465, also follow the next section.
SMTPS (port 465)
The deprecated method of securing SMTP is using the wrapper mode which uses the system service smtps as a non-standard service and runs on port 465.
To enable it uncomment the following lines in
/etc/postfix/master.cf
smtps inet n - n - - smtpd -o smtpd_tls_wrappermode=yes -o smtpd_sasl_auth_enable=yes
And verify that these lines are in /etc/services
:
smtps 465/tcp # Secure SMTP smtps 465/udp # Secure SMTP
If they are not there, go ahead and add them (replace the other listing for port 465). Otherwise Postfix will not start and you will get the following error:
postfix/master[5309]: fatal: 0.0.0.0:smtps: Servname not supported for ai_socktype
Extra
PostfixAdmin
PostfixAdmin is a web interface for Postfix used to manage mailboxes, virtual domains and aliases.
To use PostfixAdmin, you need a working Apache/MySQL/PHP setup as described in Apache HTTP Server.
For IMAP functionality, you will need to install php-imap and uncomment extension=imap
in /etc/php/php.ini
.
Next, install postfixadmin.
Edit the PostfixAdmin configuration file:
/etc/webapps/postfixadmin/config.inc.php
$CONF['configured'] = true; // correspond to dovecot maildir path /home/vmail/%d/%u $CONF['domain_path'] = 'YES'; $CONF['domain_in_mailbox'] = 'NO'; $CONF['database_type'] = 'mysqli'; $CONF['database_host'] = 'localhost'; $CONF['database_user'] = 'postfix_user'; $CONF['database_password'] = 'hunter2'; $CONF['database_name'] = 'postfix_db'; // globally change all instances of ''change-this-to-your.domain.tld'' // to an appropriate value
If installing dovecot and you changed the password scheme in dovecot (to SHA512-CRYPT for example), reflect that with postfix
/etc/webapps/postfixadmin/config.inc.php
$CONF['encrypt'] = 'dovecot:SHA512-CRYPT';
As of dovecot 2, dovecotpw has been deprecated. You will also want to ensure that your config reflects the new binary name.
/etc/webapps/postfixadmin/config.inc.php
$CONF['dovecotpw'] = "/usr/sbin/doveadm pw";
Create the Apache configuration file:
/etc/httpd/conf/extra/httpd-postfixadmin.conf
Alias /postfixadmin "/usr/share/webapps/postfixAdmin" <Directory "/usr/share/webapps/postfixAdmin"> DirectoryIndex index.html index.php AllowOverride All Options FollowSymlinks Require all granted </Directory>
To only allow localhost access to postfixadmin (for heightened security), add this to the previous <Directory> directive:
Order Deny,Allow Deny from all Allow from 127.0.0.1
Now, include httpd-postfixadmin.conf to /etc/httpd/conf/httpd.conf
:
# PostfixAdmin configuration Include conf/extra/httpd-postfixadmin.conf
Finally, navigate to http://127.0.0.1:80/postfixadmin/setup.php to finish the setup. Generate your setup password hash at the bottom of the page once it is done. Write the hash to the config file
/etc/webapps/postfixadmin/config.inc.php
$CONF['setup_password'] = 'yourhashhere';
Now you can create a superadmin account at http://127.0.0.1:80/postfixadmin/setup.php
/etc/webapps/postfixadmin
to the open_basedir
line in /etc/php/php.ini
.php -l /etc/webapps/postfixadmin/config.inc.php
.Blacklist incoming emails
Manually blacklisting incoming emails by sender address can easily be done with Postfix.
Create and open /etc/postfix/blacklist_incoming
file and append sender email address:
user@blacklistdomain.com REJECT
Then use the postmap
command to create a database:
# postmap hash:blacklist_incoming
Add the following code before the first permit rule in main.cf
:
smtpd_recipient_restrictions = check_sender_access hash:/etc/postfix/blacklist_incoming
Finally restart postfix.service
.
Postgrey
Postgrey can be used to enable greylisting for a Postfix mail server.
Installation
Install the postgrey package. To get it running quickly edit the Postfix configuration file and add these lines:
/etc/postfix/main.cf
smtpd_recipient_restrictions = check_policy_service inet:127.0.0.1:10030
Then start/enable the postgrey
service. Afterwards, reload the postfix
service. Now greylisting should be enabled.
Configuration
Configuration is done via editing the greylist.service
file. First copy it over to edit it.
# cp /usr/lib/systemd/system/postgrey.service /etc/systemd/system/
Now you can edit it. For example, to add automatic whitelisting (successful deliveries are whitelisted and don't have to wait any more), you could add the --auto-whitelist-clients=N
option and replace N
by a suitably small number (or leave it at its default of 5).
...actually, the preferred method should be the override:
cat /etc/systemd/system/postgrey.service.d/override.conf
[Service] ExecStart= ExecStart=/usr/bin/postgrey --inet=127.0.0.1:10030 \ --pidfile=/run/postgrey/postgrey.pid \ --group=postgrey --user=postgrey \ --daemonize \ --greylist-text="Greylisted for %%s seconds" \ --auto-whitelist-clients
Troubleshooting
If you specify --unix=/path/to/socket and the socket file is not created ensure you have removed the default --inet=127.0.0.1:10030 from the service file.
For a full documentation of possible options see perldoc postgrey
.
SpamAssassin
Install the spamassassin package.
Go over /etc/mail/spamassassin/local.cf
and configure it to your needs.
Spam Assassin rule update
Update the SpamAssassin matching patterns and compile them:
# sa-update && sa-compile
You will want to run this periodically, the best way to do so is by setting up a Systemd/Timers.
Create the following service, which will run these commands:
/etc/systemd/system/spamassassin-update.service
[Unit] Description=spamassassin housekeeping stuff [Service] #User=spamd #Group=spamd Type=oneshot # remove --allowplugins, if you do not want plugin updates from SA. ExecStart=/bin/sh -c '/usr/bin/vendor_perl/sa-update --allowplugins && {\ /usr/bin/vendor_perl/sa-compile --quiet;\ /usr/bin/systemctl -q --no-block try-restart spamassassin.service; }' SuccessExitStatus=1 # uncomment the following ExecStart line to train SA's bayes filter # and specify the path to the mailbox that contains spam email(s) #ExecStart=/usr/bin/vendor_perl/sa-learn --spam <path_to_your_spam_mailbox>
Then create the timer, which will execute the previous service daily:
/etc/systemd/system/spamassassin-update.timer
[Unit] Description=spamassassin house keeping [Timer] OnCalendar=daily Persistent=true [Install] WantedBy=timers.target
Now you can start and enable spamassassin-update.timer
.
SpamAssassin stand-alone generic setup
Edit /etc/postfix/master.cf
and add the content filter under smtp.
smtp inet n - n - - smtpd -o content_filter=spamassassin
Also add the following service entry for SpamAssassin
spamassassin unix - n n - - pipe flags=R user=spamd argv=/usr/bin/vendor_perl/spamc -e /usr/bin/sendmail -oi -f ${sender} ${recipient}
Now you can start and enable spamassassin.service
.
SpamAssassin combined with Dovecot LDA / Sieve (Mailfiltering)
Set up LDA and the Sieve-Plugin as described in Dovecot#Sieve. But ignore the last line mailbox_command...
.
Instead add a pipe in /etc/postfix/master.cf
:
dovecot unix - n n - - pipe flags=DRhu user=vmail:vmail argv=/usr/bin/vendor_perl/spamc -u spamd -e /usr/lib/dovecot/dovecot-lda -f ${sender} -d ${recipient}
And activate it in /etc/postfix/main.cf
:
virtual_transport = dovecot
SpamAssassin combined with Dovecot LMTP / Sieve
Set up the LMTP and Sieve as described in Dovecot#Sieve.
Edit /etc/dovecot/conf.d/90-plugins.conf
and add:
sieve_before = /etc/dovecot/sieve.before.d/ sieve_extensions = +vnd.dovecot.filter sieve_plugins = sieve_extprograms sieve_filter_bin_dir = /etc/dovecot/sieve-filter sieve_filter_exec_timeout = 120s #this is often needed for the long running spamassassin scans, default is otherwise 10s
Create the directory and put spamassassin in as a binary that can be ran by dovecot:
# mkdir /etc/dovecot/sieve-filter # ln -s /usr/bin/vendor_perl/spamc /etc/dovecot/sieve-filter/spamc
Create a new file, /etc/dovecot/sieve.before.d/spamassassin.sieve
which contains:
require [ "vnd.dovecot.filter" ]; filter "spamc" [ "-d", "127.0.0.1", "--no-safe-fallback" ];
Compile the sieve rules spamassassin.svbin
:
# cd /etc/dovecot/sieve.before.d # sievec spamassassin.sieve
Finally, restart dovecot.service
.
Call ClamAV from SpamAssassin
Install and setup clamd as described in ClamAV.
Follow one of the above instructions to call SpamAssassin from within your mail system.
Install the perl-cpanplus-dist-arch package. Then install the ClamAV perl library as follows:
# /usr/bin/vendor_perl/cpanp -i File::Scan::ClamAV
Add the 2 files from http://wiki.apache.org/spamassassin/ClamAVPlugin into /etc/mail/spamassassin/
.
Edit /etc/mail/spamassassin/clamav.pm
and update $CLAM_SOCK
to point to your Clamd socket location (default is /var/lib/clamav/clamd.sock
).
Finally, restart spamassassin.service
.
Using Razor
Make sure you have installed SpamAssassin first, then:
Register with Razor.
# mkdir /etc/mail/spamassassin/razor # chown spamd:spamd /etc/mail/spamassassin/razor # sudo -u spamd -s $ cd /etc/mail/spamassassin/razor $ razor-admin -home=/etc/mail/spamassassin/razor -register $ razor-admin -home=/etc/mail/spamassassin/razor -create $ razor-admin -home=/etc/mail/spamassassin/razor -discover
Tell SpamAssassin about Razor, add
razor_config /etc/mail/spamassassin/razor/razor-agent.conf
to /etc/mail/spamassassin/local.cf
.
Tell Razor about itself, add
razorhome = /etc/mail/spamassassin/razor/
to /etc/mail/spamassassin/razor/razor-agent.conf
Finally, restart spamassassin.service
.
Hide the sender's IP and user agent in the Received header
This is a privacy concern mostly, if you use Thunderbird and send an email. The received header will contain your LAN and WAN IP and info about the email client you used. (Original source: AskUbuntu) What we want to do is remove the Received header from outgoing emails. This can be done by the following steps:
Add this line to main.cf
smtp_header_checks = regexp:/etc/postfix/smtp_header_checks
Create /etc/postfix/smtp_header_checks with this content:
/^Received: .*/ IGNORE /^User-Agent: .*/ IGNORE
Finally, restart postfix.service
Postfix in a chroot jail
Postfix is not put in a chroot jail by default. The Postfix documentation [1] provides details about how to accomplish such a jail. The steps are outlined below and are based on the chroot-setup script provided in the postfix source code.
First, go into the master.cf
file in the directory /etc/postfix
and change all the chroot entries to 'yes' (y) except for the services qmgr
, proxymap
, proxywrite
, local
, and virtual
Second, create two functions that will help us later with copying files over into the chroot jail (see last step)
CP="cp -p"
cond_copy() { # find files as per pattern in $1 # if any, copy to directory $2 dir=`dirname "$1"` pat=`basename "$1"` lr=`find "$dir" -maxdepth 1 -name "$pat"` if test ! -d "$2" ; then exit 1 ; fi if test "x$lr" != "x" ; then $CP $1 "$2" ; fi }
Next, make the new directories for the jail:
set -e umask 022
POSTFIX_DIR=${POSTFIX_DIR-/var/spool/postfix} cd ${POSTFIX_DIR}
mkdir -p etc lib usr/lib/zoneinfo test -d /lib64 && mkdir -p lib64
Find the localtime file
lt=/etc/localtime if test ! -f $lt ; then lt=/usr/lib/zoneinfo/localtime ; fi if test ! -f $lt ; then lt=/usr/share/zoneinfo/localtime ; fi if test ! -f $lt ; then echo "cannot find localtime" ; exit 1 ; fi rm -f etc/localtime
Copy localtime and some other system files into the chroot's etc
$CP -f $lt /etc/services /etc/resolv.conf /etc/nsswitch.conf etc $CP -f /etc/host.conf /etc/hosts /etc/passwd etc ln -s -f /etc/localtime usr/lib/zoneinfo
Copy required libraries into the chroot using the previously created function cond_copy
cond_copy '/usr/lib/libnss_*.so*' lib cond_copy '/usr/lib/libresolv.so*' lib cond_copy '/usr/lib/libdb.so*' lib
And don't forget to reload postfix.
Rule-based mail processing
With policy services one can easily finetune postfix' behaviour of mail delivery. postfwd and policydAUR provide services to do so. This allows you to e.g. implement time-aware grey- and blacklisting of senders and receivers as well as SPF policy checking.
Policy services are standalone services and connected to Postfix like this:
/etc/postfix/main.cf
smtpd_recipient_restrictions = ... check_policy_service unix:/run/policyd.sock check_policy_service inet:127.0.0.1:10040
Placing policy services at the end of the queue reduces load, as only legitimate mails are processed. Be sure to place it before the first permit statement to catch all incoming messages.
DANE (DNSSEC)
Resource Record
DANE supports several types of records, however not all of them are suitable in postfix.
Certificate usage 0 is unsupported, 1 is mapped to 3 and 2 is optional, thus it is recommendet to publish a "3" record. More on Resource Records.
Configuration
Opportunistic DANE is configured this way:
/etc/postfix/main.cf
smtpd_use_tls = yes smtp_dns_support_level = dnssec smtp_tls_security_level = dane
/etc/postfix/master.cf
dane unix - - n - - smtp -o smtp_dns_support_level=dnssec -o smtp_tls_security_level=dane
To use per-domain policies, e.g. opportunistic DANE for example.org and mandatory DANE for example.com, use something like this:
/etc/postfix/main.cf
indexed = ${default_database_type}:${config_directory}/ # Per-destination TLS policy # smtp_tls_policy_maps = ${indexed}tls_policy # default_transport = smtp, but some destinations are special: # transport_maps = ${indexed}transport
transport
example.com dane example.org dane
tls_policy
example.com dane-only
smtp_tls_security_level
to dane-only
. Be aware that this makes postfix tempfail on all delivieres that do not use DANE at all!Full documentation is found here.
Sender Policy Framework
To use the Sender Policy Framework with Postfix, install python-postfix-policyd-spfAUR.
Edit /etc/python-policyd-spf/policyd-spf.conf
to your needs. An extensively commented version can be found at /etc/python-policyd-spf/policyd-spf.conf.commented
.
Pay some extra attention to the HELO check policy, as standard settings strictly reject HELO failures.
In the main.cf add a timeout for the policyd:
/etc/postfix/main.cf
policy-spf_time_limit = 3600s
Then add a transport
/etc/postfix/master.cf
policy-spf unix - n n - 0 spawn user=nobody argv=/usr/bin/policyd-spf
Lastly you need to add the policyd to the smtpd_recipient_restrictions
. To minimize load put it to the end of the restrictions:
/etc/postfix/main.cf
smtpd_recipient_restrictions= ... permit_sasl_authenticated permit_mynetworks reject_unauth_destination check_policy_service unix:private/policy-spf
You can test your Setup with the following:
/etc/python-policyd-spf/policyd-spf.conf
defaultSeedOnly = 0
Sender Rewriting Scheme
To use the Sender Rewriting Scheme with Postfix, install postsrsdAUR and adjust the settings:
/etc/postsrsd/postsrsd
SRS_DOMAIN=yourdomain.tld SRS_EXCLUDE_DOMAINS=yourotherdomain.tld,yet.anotherdomain.tld SRS_SEPARATOR== SRS_SECRET=/etc/postsrsd/postsrsd.secret SRS_FORWARD_PORT=10001 SRS_REVERSE_PORT=10002 RUN_AS=postsrsd CHROOT=/usr/lib/postsrsd
Enable and start the daemon, making sure it runs after reboot as well. Then configure postfix accordingly by tweaking the following lines:
/etc/postfix/main.cf
sender_canonical_maps = tcp:localhost:10001 sender_canonical_classes = envelope_sender recipient_canonical_maps = tcp:localhost:10002 recipient_canonical_classes= envelope_recipient,header_recipient
Restart postfix and start forwarding mail.
See also
- Out of Office for Squirrelmail [dead link 2017-08-23]
- Postfix Ubuntu documentation