Почтовый сервер на базе OpenBSD 6.0
Версия от 01:44, 27 октября 2016; Admwiki (обсуждение | вклад)
Вступление
Перевод статьи Chess Griffin с небольшим количеством комментариев от переводчика, в основном связанных с тем, что с момента релиза OpenBSD 5.6, система стала еще лучше!
Цель
Создать достаточно безопасный почтовый сервер на базе OpenBSD и нескольких пакетов. OpenSMTPD, spamd, pf и httpd входят в состав базовой системы. Дополнительно потребуются ClamAV, ClamSMTP, SpamAssassin, SpamPD, DKIMproxy, Dovecot, Dovecot-Pigeonhole и Roundcube.
Окончательный результат
Обработка входящих сообщений
pf -> spamd -> opensmtpd -> clamsmtpd -> clamd -> clamsmtpd -> opensmtpd -> spampd -> SpamAssassin -> spampd -> opensmtpd -> deliver to dovecot/lmtp
Обработка исходящих сообщений
opensmtpd -> clamsmtpd -> clamd -> clamsmtpd -> opensmtpd -> dkimproxy -> opensmtpd -> relay out
Дополнительно
Доступ посредством IMAP (SSL): Dovecot
Доступ к почте через веб-интерфейса (SSL): httpd и Roundcube
Почему OpenBSD?
Это прекрасная операционная система, созданная и поддерживаемая многими умными людьми. Кроме того, мне нравится, что большое количество великолепного программного обеспечения включено в базовую систему. Если вы найдёте это руководство полезным или откроете как восхитительна OpenBSD, пожалуйста подумайте над тем, чтобы поддержать проект — это может быть приобретение набора компакт дисков[1] или сделав пожертвование. Команда разработчиков OpenBSD отлично выполняет свою работу, которая приносит пользу всему сообществу и ваша поддержка не будет лишней!
Зачем SpamAssassin в дополнение к spamd?
Spamd отлично работает, не создавая лишней нагрузки. Он отлавливает большую часть моего спама (более 95 %), так что я почти решил отказаться от возни со SpamAssassin. Но подумав, решил что будет интересно попробовать интегрировать их оба.
Почему не <вставьте имя любимой операционной системы или программы>?
Никогда не слышал об этом. ;-)
Why bother with setting up your own email server to begin with? Why not just keep using Gmail?
I used to run my own email server back when I hosted the Linux Reality podcast and decided it would be a fun exercise to try it again. The email server I set up using the steps in this guide might become my primary email server. Or, I might take the server down tomorrow and go back to using AOL and working on my Geocities page. Who knows?
Assumptions
This guide assumes an understanding of how to install and configure OpenBSD and an understanding of networking and email, both in general and in regards to OpenBSD in particular. Additionally, this guide assumes an understanding of how to install packages with a properly configured $PKG_PATH, how to work from the command line and edit configuration files, how to change DNS records and MX records, and other general nuts and bolts. These kinds of basic topics will not be covered in this guide.
Disclaimer
I am an ordinary OpenBSD user. I am not a sysadmin, developer, programmer, kung-fu master, or expert in any of these areas. This guide is mainly a writeup for myself so I can replicate these steps in the future. If someone finds it helpful, fine, but it is by no means the only way or even the best way to configure an email server. There are most likely mistakes in this guide, so take it for what it’s worth and YMMV. If your email breaks because of this guide, then don’t run your own email server. Feedback and corrections are welcome.
Updates
Updated the last line of example smtpd.conf from "for any" to "for domain <vdomains>". Thanks to Christoph on the opensmtpd-misc mailing list. Removed bit about enabling pf since it's enabled by default. Duh. Also changed notations of port 587 to 'submission' which is the name of that port in /etc/services. Thanks to rjc.
Resources
- OpenBSD FAQ (required)
- OpenBSD man pages (required)
- OpenSMTPD wiki
- Helpful thread on OpenSMTPD mailing list re: tagging and proxying
- http://www.kernel-panic.it/openbsd/mail/ (the bits about ClamAV and SpamAssassing are helpful)
- https://coderwall.com/p/eejzja/simple-smtp-server-with-opensmtpd
- http://blog.ehouse.io/mail-server-basic-smtp.html
- http://blog.admiral0.it/computing/mail-server-with-opensmtpd-dovecot-and-amavisdspamassassin
Initial Setup
- Install OpenBSD 5.6. If using the auto-partitioner, make sure enough space is allocated to /usr and /usr/src to allow for extracting the sources (below). Edit /etc/rc.conf.local and add «-s» to ntpd_flags so time is set at boot if desired.
- Add a rule to default /etc/pf.conf to allow incoming ssh connections, such as:
# cat /etc/pf.conf
…
pass in on egress proto tcp to any port ssh
…
- Reload pf with:
# pfctl -f /etc/pf.conf
- Update the system by fetching the sources via ftp and patching.
- Set up $PKG_PATH to install packages.
- Configure MX records etc. at domain registrar, perhaps with an unused domain for testing purposes.
OpenSMTPD и spamd
- Read the man page for smtpd and smtpd.conf and review the configuration files.
- Set up virtual users and virtual domains:
# cat /etc/mail/vusersjoe@example.com joe@example.com joejoe@example.net joe@example.net joe# cat /etc/mail/vdomainsexample.comexample.net
- Create SSL certificates as described in man 5 smtpd.conf:
# openssl genrsa -out /etc/ssl/private/mail.example.com.key 4096# openssl req -new -x509 -key /etc/ssl/private/mail.example.com.key -out /etc/ssl/mail.example.com.crt -days 365# chmod 600 /etc/ssl/mail.example.com.crt# chmod 600 /etc/ssl/private/mail.example.com.key
- Create ~/Maildir for user («joe» in this example).
- Edit /etc/mail/smtpd.conf so it listens on egress with tls (for incoming mail) and egress port 587 (submission) with tls and authentication (for outgoing mail), accepts mail for virtual users and virtual domains, and delivers this mail to Maildir. Note that the smtpd.conf man page clearly says: «For each message processed by the daemon, the filter rules are evaluated in sequential order, from first to last. The first matching rule decides what action is taken.» Therefore, the order of the rules in smtpd.conf is very important and will become more important as additional bits are added (e.g. for clamsmtp, spampd, and dkimproxy).
# cat /etc/mail/smtpd.confpki mail.example.com certificate "/etc/ssl/mail.example.com.crt"pki mail.example.com key "/etc/ssl/private/mail.example.com.key"listen on lo0listen on egress tls pki mail.example.com auth-optionallisten on egress port submission tls-require pki mail.example.com authtable aliases db:/etc/mail/aliases.dbtable vusers file:/etc/mail/vuserstable vdomains file:/etc/mail/vdomainsaccept for local alias <aliases> deliver to maildiraccept from any for domain <vdomains> virtual <vusers> deliver to maildiraccept from local for any relay
- Edit pf.conf to allow connections on smtp port 25 and port 587, such as:
# cat /etc/pf.conf...pass in on egress proto tcp to any port smtppass in on egress proto tcp to any port submission...
- Reload pf and start /etc/rc.d/smtpd.
- Test sending mail to/from the user’s account. Since there is no imap client yet, might want to install mutt or something similar and point to the user’s ~/Maildir to check incoming mail. The user should be able to connect to OpenSMTPD on port 587 from an outside client to send mail through OpenSMTPD to another party. Sending outbound mail from the command line should also work. Perhaps telnet into the server or run a couple of SMTP checks against the server like this one to verify things are working correctly. The session transcript should look something like this:
Connecting to 123.456.789.000220 mail.example.com ESMTP OpenSMTPD [624 ms]EHLO MXTB-PWS3.mxtoolbox.com250-mail.example.com Hello MXTB-PWS3.mxtoolbox.com [64.20.227.133], pleased to meet you250-8BITMIME250-ENHANCEDSTATUSCODES250-SIZE 36700160250-DSN250-STARTTLS250 HELP [640 ms]MAIL FROM: <supertool@mxtoolbox.com>250 2.0.0: Ok [640 ms]RCPT TO: <test@example.com>550 Invalid recipient [640 ms]MXTB-PWS3v2 3260ms
- If that works, set up spamd. This is a very simple and standard setup and there are lots of resources out there on how to do this, but here is the shorthand: Add spamd_flags="-v" to /etc/rc.conf.local. Edit /etc/mail/spamd.conf to add override/whitelist if desired (file /etc/mail/nospamd in sample pf rules). Add spamd pf rules from example /etc/pf.conf and comment out prior rule that passed smtp on egress (because now we want incoming mail to be redirected to spamd running on localhost port 8025):
# cat /etc/pf.conf...#pass in on egress proto tcp to any port smtppass in on egress proto tcp to any port submission# rules for spamd(8)table <spamd-white> persisttable <nospamd> persist file "/etc/mail/nospamd"pass in on egress proto tcp from any to any port smtp rdr-to 127.0.0.1 port spamdpass in on egress proto tcp from <nospamd> to any port smtppass in log on egress proto tcp from <spamd-white> to any port smtppass out log on egress proto tcp to any port smtp...- Reload pf and start /etc/rc.d/spamd. Check netstat to see if spamd is listening on port 8025:
# netstat -na -f inet
- Send test emails again and check logs and 'spamdb' to see if email is getting greylisted. Once spamd is working, those third-party SMTP checks won’t work because spamd is intercepting incoming mail. Same with telnet, if you can stand waiting for the stuttering. ;-) Anyway, now the session transcript should look something like this:
Connecting to 123.456.789.000220 mail.example.com ESMTP spamd IP-based SPAM blocker; Sat Jan 31 11:33:21 2015 [11716 ms]EHLO MXTB-PWS3.mxtoolbox.com250 Hello, spam sender. Pleased to be wasting your time. [640 ms]MAIL FROM: <supertool@mxtoolbox.com>250 You are about to try to deliver spam. Your time will be spent, for nothing. [640 ms]RCPT TO: <test@example.com>250 This is hurting you more than it is hurting me. [640 ms]MXTB-PWS3v2 14602ms- Haha. Love spamd.
- So here is what’s happening:
- Incoming mail:
- pf -> relay to spamd -> send to opensmtpd on lo0 -> deliver to maildir
- Outoing mail:
- opensmtpd on lo0 -> relay out
ClamAV and ClamSMTP
- Install clamav and clamsmtp from packages.
- Edit /etc/freshclam.conf — comment out the «Example» line and uncomment the «DatabaseMirror» line and add the relevant country code in place of the «XY.»
# cat /etc/freshclam.conf#Example...DatabaseMirror db.us.clamav.net...- Run ‘freshclam’ to update the database. Add a freshclam command to root’s crontab to have periodic updates:
20 * * * * /usr/local/bin/freshclam >/dev/null 2>&1
- Once freshclam has updated the database, edit /etc/clamd.conf. Comment out the «Example» line, uncomment «TCPSocket» and «TCPAddr» lines and change them so clamd listens on port 3310 at 127.0.0.1.
# cat /etc/clamd.conf#Example...TCPSocket 3310...TCPAddr 127.0.0.1...- Add «clamd» to pkg_scripts in /etc/rc.conf.local and then start clamd. Check netstat -na -f inet to see if clamd is running on 127.0.0.1:3310. Check out both /etc/freshclam.conf and /etc/clamd.conf to look at logging options or actions (in VirusEvent) to take when a virus is found. Can set it up so it drops an email into root’s mailbox when a virus is found.
- Now, set up clamsmtp, which is a proxy for clamd. Two config files will be used, one for incoming mail and one for outgoing mail. OpenSMTPD will accept mail, send it to clamsmtp on one port for incoming mail (10025) and a different port (10027) for outgoing mail. Clamsmtp will run the mail through clamd, and then return it to OpenSMTPD for incoming mail (10026) or outgoing mail (10028). Depending on which port the mail is returned to, OpenSMTPD will tag it CLAM_IN or CLAM_OUT.
- So copy /etc/clamsmtpd.conf and create /etc/clamsmtpd-in.conf and /etc/clamsmtpd-out.conf. Modify the files like so:
# cat /etc/clamsmtpd-in.confOutAddress: 10026...Listen: 0.0.0.0:10025...ClamAddress: 127.0.0.1:3310...# cat /etc/clamsmtpd-out.confOutAddress: 10028...Listen: 0.0.0.0:10027...ClamAddress: 127.0.0.1:3310...
- Start them both:
# /usr/local/sbin/clamsmtpd -f /etc/clamsmtpd-in.conf# /usr/local/sbin/clamsmtpd -f /etc/clamsmtpd-out.conf- (add something similar to /etc/rc.local so they start at boot)
- Edit /etc/mail/smtpd.conf so it looks like this:
# cat /etc/mail/smtpd.confpki mail.example.com certificate "/etc/ssl/mail.example.com.crt"pki mail.example.com key "/etc/ssl/private/mail.example.com.key"listen on lo0listen on lo0 port 10026 tag CLAM_IN # incoming maillisten on lo0 port 10028 tag CLAM_OUT # outgoing maillisten on egress tls pki mail.example.com auth-optionallisten on egress port submission tls-require pki mail.example.com authtable aliases db:/etc/mail/aliases.dbtable vusers file:/etc/mail/vuserstable vdomains file:/etc/mail/vdomainsaccept for local alias <aliases> deliver to maildir# tagged mail returned from clamsmtpd either deliver or relayaccept tagged CLAM_IN for domain <vdomains> virtual <vusers> deliver to maildiraccept tagged CLAM_OUT for any relay# start here - untagged mail is sent to clamsmtpdaccept from any for domain <vdomains> relay via smtp://127.0.0.1:10025 # incoming mailaccept from local for any relay via smtp://127.0.0.1:10027 # outgoing mail- So here is what’s happening:
- Incoming mail:
- pf -> relay to spamd -> send to opensmtpd on lo0 -> relay untagged mail to clamsmtpd on port 10025 -> relay to clamd on port 3310 -> return to clamsmtpd -> return to opensmtpd on lo0 port 10026 and tag it CLAM_IN -> deliver to maildir
- Outoing mail:
- opensmtpd on lo0 -> relay untagged mail to clamsmtpd on port 10027 -> relay to clamd on port 3310 -> return to clamsmtpd -> return to opensmtpd on lo0 port 10028 and tag it CLAM_OUT -> relay out
- Send some emails both ways. This should be in the header:
X-Virus-Scanned: ClamAV using ClamSMTP
SpamAssassin and SpamPD
- Install p5-Mail-SpamAssassin and spampd from packages.
- Edit /etc/mail/spamassassin/local.cf and uncomment the «rewrite_header» line.
- Spampd will be used as a proxy like clamsmtp. For purposes of this guide, only incoming mail will be scanned. Spampd by default runs on port 10025 but that port is already being used for clamsmtp. So, add the following to /etc/rc.conf.local:
spampd_flags="--port=10035 --relayhost=127.0.0.1:10036 --tagall -aw"- With these flags, spampd will listen on port 10035 and after processing the mail through SpamAssassin, spampd will relay the mail back to port 10036, where OpenSMTPD will be listening.
- UPDATE: spampd seems to have trouble binding to the right port (10035 in this case) upon a reboot even with those spampd_flags set in /etc/rc.conf.local. It tries to bind to 10025 which, as noted previously, is being used by clamsmtp, and therefore spampd fails to work and incoming mail has no place to go when opensmtpd tries to relay it to spampd. I have to manually log in and kick spampd to get it to bind to 10035. Still investigating a solution other than changing all the ports around …
- Add «spamassassin» and «spampd» to pkg_scripts in /etc/rc.conf.local and then start both spamassassin and spampd. A «netstat -na -f inet» should show spampd listening on port 10035.
- Once spampd was processing mail, there were errors in /var/log/maillog along the lines of: «spampd Insecure dependency -T switch at Socket.pm» and it wasn’t working. Turns out spampd needs patching for newer Perl. See this: https://github.com/mpaperno/spampd/issues/2. Here is a patch to /usr/local/sbin/spampd (also found here):
--- spampd.orig Thu Jan 29 23:19:45 2015+++ spampd Thu Jan 29 23:21:31 2015@@ -824,6 +824,22 @@ if ( $logsock !~ /^(unix|inet)$/ ) {usage(0);}+# Untaint some options provided by admin command line.+$pidfile =~ /^(.*)$/;+$pidfile = $1;++$relayhost =~ /^(.*)$/;+$relayhost = $1;++$relayport =~ /^(.*)$/;+$relayport = $1;++$host =~ /^(.*)$/;+$host = $1;++$port =~ /^(.*)$/;+$port = $1;+if ( $options{tagall} ) { $tagall = 1; }if ( $options{'log-rules-hit'} ) { $rh = 1; }if ( $options{debug} ) { $debug = 1; $nsloglevel = 4; }
- Restart spampd after applying that patch.
- Now, modify /etc/mail/smtpd.conf similar to what was done for clamsmtp:
# cat /etc/mail/smtpd.confpki mail.example.com certificate "/etc/ssl/mail.example.com.crt"pki mail.example.com key "/etc/ssl/private/mail.example.com.key"listen on lo0listen on lo0 port 10026 tag CLAM_IN # incoming maillisten on lo0 port 10028 tag CLAM_OUT # outgoing maillisten on lo0 port 10036 tag SPAM_IN # incoming maillisten on egress tls pki mail.example.com auth-optionallisten on egress port submission tls-require pki mail.example.com authtable aliases db:/etc/mail/aliases.dbtable vusers file:/etc/mail/vuserstable vdomains file:/etc/mail/vdomainsaccept for local alias <aliases> deliver to maildir# tagged mail returned from spampd deliver to maildiraccept tagged SPAM_IN for domain <vdomains> virtual <vusers> deliver to maildir# tagged mail returned from clamsmtpd either send to spampd or relayaccept tagged CLAM_IN for any relay via smtp://127.0.0.1:10035 # send to spampdaccept tagged CLAM_OUT for any relay# start here - untagged mail is sent to clamsmtpdaccept from any for domain <vdomains> relay via smtp://127.0.0.1:10025 # incoming mailaccept from local for any relay via smtp://127.0.0.1:10027 # outgoing mail
- There were still some errors in /var/log/maillog. First, there was something like this:
Feb 03 16:48:44 server spampd[22524]: spf: lookup failed: available_nameservers: No DNS servers available!Feb 03 16:48:44 server spampd[22524]: rules: failed to run USER_IN_DEF_DKIM_WL test, skipping: (available_nameservers: No DNS servers available!)- Turns out, SpamAssassin had broken DNS lookups. Here is the patch to /usr/local/libdata/perl5/site_perl/Mail/SpamAssassin/DnsResolver.pm (also found here):
--- DnsResolver.pm.orig Fri Feb 7 03:36:28 2014+++ DnsResolver.pm Thu Nov 13 16:04:01 2014@@ -204,8 +204,10 @@@ns_addr_port = @{$self->{conf}->{dns_servers}};dbg("dns: servers set by config to: %s", join(', ',@ns_addr_port));} elsif ($res) { # default as provided by Net::DNS, e.g. /etc/resolv.conf- @ns_addr_port = map(untaint_var("[$_]:" . $res->{port}),- @{$res->{nameservers}});+ my @ns = $res->UNIVERSAL::can('nameservers') ? $res->nameservers+ : @{$res->{nameservers}};+ my $port = $res->UNIVERSAL::can('port') ? $res->port : $res->{port};+ @ns_addr_port = map(untaint_var("[$_]:" . $port), @ns);dbg("dns: servers obtained from Net::DNS : %s", join(', ',@ns_addr_port));}return @ns_addr_port;
- Then, there was this:
Feb 03 16:48:44 server spampd[22524]: plugin: eval failed: bayes: (in learn) locker: safe_lock: cannot create tmp lockfile /var/spampd/.spamassassin/bayes.lock.mail.example.com.22524 for /var/spampd/.spamassassin/bayes.lock: Permission denied- It appeared that although /var/spampd was set to _spampd:_spampd, the /var/spampd/.spamassassin was set to root:_spampd and the permissions were 700 (IIRC). Anyway, chown that directory to also be _spampd:_spampd and then it appears to work fine.
- So now here is what’s happening:
- Incoming mail:
- pf -> relay to spamd -> send to opensmtpd on lo0 -> relay untagged mail to clamsmtpd on port 10025 -> relay to clamd on port 3310 -> return to clamsmtpd -> return to opensmtpd on lo0 port 10026 and tag it CLAM_IN -> relay tagged CLAM_IN mail to spampd on port 10035 -> run it through SpamAssassin -> return to spampd -> return to opensmtpd on lo0 port 10036 and tag it SPAM_IN -> deliver to maildir
- Outoing mail (unchanged from before since outgoing mail is not sent to spampd):
- opensmtpd on lo0 -> relay untagged mail to clamsmtpd on port 10027 -> relay to clamd on port 3310 -> return to clamsmtpd -> return to opensmtpd on lo0 port 10028 and tag it CLAM_OUT -> relay out
- Test again, both ways. Use the GTUBE test to see if it’s flagged as spam. There should be SpamAssassin headers in the incoming email. SpamAssassin can be further set up for Bayesian training and cron entries for running sa-learn on designated directories.
DKIMproxy
- Follow the steps here to create public and private keys that will be used by DKIMproxy.
- Create a TXT record for each domain the server will be hosting that looks something like this:
selector1._domainkey v=DKIM1; k=rsa; p=KEY_GOES_HERE TXT 1800 TTL
- Install dkimproxy from ports (no packages available for OpenBSD 5.6). It has no dependencies that aren’t already pulled in from prior packages so it’s an easy and quick build.
- Edit /etc/dkimproxy_out.conf so it looks something like this (note that the default ports are different so they don’t conflict with the earlier clamsmtpd setup):
# cat /etc/dkimproxy_out.conf# specify what address/port DKIMproxy should listen on#listen 127.0.0.1:10027listen 127.0.0.1:10030# specify what address/port DKIMproxy forwards mail to#relay 127.0.0.1:10028relay 127.0.0.1:10029# specify what domains DKIMproxy can sign for (comma-separated, no spaces)#domain example.orgdomain example.com,example.net# specify what signatures to addsignature dkim(c=relaxed)signature domainkeys(c=nofws)# specify location of the private key#keyfile /full/path/to/private.keykeyfile /etc/mail/dkim/private.key# specify the selector (i.e. the name of the key record put in DNS)selector selector1...- Since SpamAssassin already does DKIM checking for incoming mail, dkimproxy is only used for outgoing mail to add the DKIM keys etc. to outgoing headers.
- Add «dkimproxy_out» to pkg_scripts in /etc/rc.conf.local and start it up. Again, check netstat -na -f inet to see if it’s listening on port 10030.
- Same drill as before. Edit /etc/mail/smtpd.conf so it looks something like this:
# cat /etc/mail/smtpd.confpki mail.example.com certificate "/etc/ssl/mail.example.com.crt"pki mail.example.com key "/etc/ssl/private/mail.example.com.key"listen on lo0listen on lo0 port 10026 tag CLAM_IN # incoming maillisten on lo0 port 10028 tag CLAM_OUT # outgoing maillisten on lo0 port 10036 tag SPAM_IN # incoming maillisten on lo0 port 10029 tag DKIM_OUT # outgoing maillisten on egress tls pki mail.example.com auth-optionallisten on egress port submission tls-require pki mail.example.com authtable aliases db:/etc/mail/aliases.dbtable vusers file:/etc/mail/vuserstable vdomains file:/etc/mail/vdomainsaccept for local alias <aliases> deliver to maildir# tagged mail returned from dkimproxy_out relay outaccept tagged DKIM_OUT for any relay# tagged mail returned from spampd deliver to maildiraccept tagged SPAM_IN for domain <vdomains> virtual <vusers> deliver to maildir# tagged mail returned from clamsmtpd either send to spampd or dkimproxy_outaccept tagged CLAM_IN for any relay via smtp://127.0.0.1:10035 # send to spampdaccept tagged CLAM_OUT for any relay via smtp://127.0.0.1:10030 # send to dkimproxy_out# start here - untagged mail is sent to clamsmtpdaccept from any for domain <vdomains> relay via smtp://127.0.0.1:10025 # incoming mailaccept from local for any relay via smtp://127.0.0.1:10027 # outgoing mail
- So now here is what’s happening:
- Incoming mail (unchanged from before since incoming mail is not using dkimproxy):
- pf -> relay to spamd -> send to opensmtpd on lo0 -> relay untagged mail to clamsmtpd on port 10025 -> relay to clamd on port 3310 -> return to clamsmtpd -> return to opensmtpd on lo0 port 10026 and tag it CLAM_IN -> -relay tagged CLAM_IN mail to spampd on port 10035 -> run it through SpamAssassin -> return to opensmtpd on lo0 port 10036 and tag it SPAM_IN -> deliver to maildir
- Outoing mail:
- opensmtpd on lo0 -> relay untagged mail to clamsmtpd on port 10027 -> relay to clamd on port 3310 -> return to clamsmtpd -> return to opensmtpd on lo0 port 10028 and tag it CLAM_OUT -> relay to dkimproxy on port 10030 -> add DKIM headers -> return to opensmtpd on lo0 port 10029 and tag it DKIM_OUT -> relay out
- Send an email and look at the headers. There should be some DKIM headers for the domain like these:
DKIM-Signature: v=1; a=rsa-sha1; c=relaxed; d=example.com; h=from:date:message-id:to:subject; s=selector1; bh=[KEY HASH]DomainKey-Signature: a=rsa-sha1; c=nofws; d=example.com; h=from:date:message-id:to:subject; q=dns; s=selector1; b=[KEY HASH]
Примечания
- ↑ С релиза 6.1, OpenBSD не будет распространяться на CD, но вы по прежнему можете приобрести различные предметы с символикой OpenBSD. прим. переводчика