| Version: | 2.0 |
|---|---|
| Source: | https://app.box.com/s/lsz0b4w8cmu46qaz02w39far0djk1uny |
| Keywords: | Postfix Mail server management, Cyrus-SASL, Dovecot, MySQL, Virtual Domains, Alias Domains |
Copyright (C) Umar Draz <[email protected]>
1. Requirements 2. MySQL Server Installation 3. Postfix and Dovecot 4. Web Server Installation 5. Postfix vManager Installation 6. OpenDKIM (Domain Keys)
- Postfix which supports virtual domains and mailboxes including vda patch.
- a compatible IMAP/POP3 server (such as Dovecot and Courier), but in this howto we will only discuss Dovecot
- PHP v4 and above with PDO and mysqli supported.
Installing MySQL 5 Server on FreeBSD is a quick and easy process. In classic fashion let’s get the process underway by updating our system.
cd /usr/ports/databases/mysql51-server/ make install clean
Add the following line to /etc/rc.conf:
echo 'mysql_enable="YES"' >> /etc/rc.conf
And start the mysql server:
/usr/local/etc/rc.d/mysql-server start
Then set a password for the MySQL root user:
/usr/local/bin/mysqladmin -u root password 'your-password'
That's All MySQL server has been installed, now lest install Postfix and Dovecot.
Let's start the Mail server Installation.
cd /usr/ports/mail/postfix make install clean
In the option list window you must select these options.
[ .. ] MYSQL [ .. ] SASL2 [ .. ] SPF [ .. ] TLS [ .. ] VDA [ .. ] DOVECOT2
And on Dovecot installation, when window appear, you must also select [ .. ] MYSQL option.
This will install the Postfix mail server, the Dovecot IMAP and POP daemons, and several supporting packages that provide services related to authentication.
After sucessfully installation of Postfix, in the next step will create database for our Postfix vManager.
Start the MySQL shell by issuing the following command. You'll be prompted to enter the root password for MySQL that you assigned during the initial setup.
mysql -u root -p
You'll be presented with an interface similar to the following:
Welcome to the MySQL monitor. Commands end with ; or \g. Your MySQL connection id is 48 Server version: 5.5.31-0ubuntu0.12.04.1 (Ubuntu) Type 'help;' or '\h' for help. Type '\c' to clear the current input statement. mysql>
Issue the following command to create a database for your mail server and switch to it in the shell:
CREATE DATABASE vmanager; USE vmanager;
Create a mail administration user called vadmin and grant it permissions on the mail database with the following commands. Please be sure to replace "vadmin_password" with a password you select for this user.
GRANT SELECT, INSERT, UPDATE, DELETE ON vmanager.* TO 'vadmin'@'localhost' IDENTIFIED BY 'vadmin_password'; FLUSH PRIVILEGES;
That's all we have sucessfully create database for our application, latter on we will restore our database schema into vmanager database when we will install Postfix vManager.
Create a virtual forwarding file called /etc/postfix/mysql_virtual_forwarders_maps.cf for forwarding emails from one email address to another, with the following contents. Be sure to replace "vadmin_password" with the password you chose earlier for the MySQL mail administrator user.
File: /usr/local/etc/postfix/mysql_virtual_forwarders_maps.cf
user = vadmin password = vadmin_password hosts = localhost dbname = vmanager query = SELECT goto FROM forwarders WHERE address='%s' AND active = '1'
Create a virtual domain configuration file for Postfix called /etc/postfix/mysql_virtual_domains_maps.cf with the following contents. Be sure to replace "vadmin_password" with the password you chose earlier for the MySQL mail administrator user.
File: /usr/local/etc/postfix/mysql_virtual_domains_maps.cf
user = vadmin password = vadmin_password hosts = localhost dbname = vmanager query = SELECT domain FROM domain WHERE domain='%s' and active='1'
Create a virtual mailbox configuration file for Postfix called /etc/postfix/mysql_virtual_mailbox_maps.cf with the following contents. Be sure to replace "vadmin_password" with the password you chose earlier for the MySQL mail administrator user.
File: /usr/local/etc/postfix/mysql_virtual_mailbox_maps.cf
user = vadmin password = vadmin_password hosts = localhost dbname = vmanager query = SELECT CONCAT(domain,'/',maildir) FROM mailbox WHERE username='%s' AND active = '1'
Create a mailbox quota limit configuration file for Postfix called /etc/postfix/mysql_virtual_mailbox_limit_maps.cf with the following contents. Be sure to replace "vadmin_password" with the password you chose earlier for the MySQL mail administrator user.
File: /usr/local/etc/postfix/mysql_virtual_mailbox_limit_maps.cf
user = vadmin password = vadmin_password hosts = localhost dbname = vmanager query = SELECT quota FROM mailbox WHERE username='%s'
Create a sender check configuration file called /etc/postfix/mysql_sender_check.cf so after smtp authentication senders can not use our mail server as open relay.
File: /usr/local/etc/postfix/mysql_sender_check.cf
user = vadmin password = vadmin_password hosts = localhost dbname = vmanager query = SELECT username FROM ( SELECT username as username FROM mailbox UNION ALL SELECT address FROM alias_domain) a where username = '%s'
Create a transport map configuration file called /etc/postfix/mysql_transport.cf with the following contents. Be sure to replace "vadmin_password" with the password you chose earlier for the MySQL mail administrator user.
File: /usr/local/etc/postfix/mysql_transport.cf
user = vadmin password = vadmin_password hosts = localhost dbname = vmanager query = SELECT destination FROM transport where domain = '%s'
Create an alias domains configuration file called /etc/postfix/mysql_virtual_alias_domains_maps.cf with the following contents. Be sure to replace "vadmin_password" with the password you chose earlier for the MySQL mail administrator user.
File: /usr/local/etc/postfix/mysql_virtual_alias_domains_maps.cf
user = vadmin
password = vadmin_password
hosts = localhost
dbname = vmanager
query = SELECT target_domain FROM alias_domain WHERE address = '%s' OR address = concat('@', SUBSTRING_INDEX('%s', '@', -1)) AND concat('@', alias_domain) = '%s' AND active = '1'
Create a parking domain configuration file called /etc/postfix/mysql_parking_domains_maps.cf with the following contents. Be sure to replace "vadmin_password" with the password you chose earlier for the MySQL mail administrator user.
File: /usr/local/etc/postfix/mysql_parking_domains_maps.cf
user = vadmin password = vadmin_password hosts = localhost dbname = vmanager query = SELECT domain FROM parking_domains WHERE domain='%s' and active = '1'
Create a virtual groups configuration file called /etc/postfix/mysql_virtual_groups_maps.cf with the following contents. Be sure to replace "vadmin_password" with the password you chose earlier for the MySQL mail administrator user.
File: /usr/local/etc/postfix/mysql_virtual_groups_maps.cf
user = vadmin password = vadmin_password hosts = localhost dbname = vmanager query = SELECT goto FROM groups WHERE address='%s' AND active = '1'
Create an alias domains relay configuration file called /etc/postfix/mysql_alias_domains.maps.cf with the following contents. Be sure to replace "vadmin_password" with the password you chose earlier for the MySQL mail administrator user.
File: /usr/local/etc/postfix/mysql_alias_domains.maps.cf
user = vadmin password = vadmin_password hosts = localhost dbname = vmanager query = SELECT DISTINCT alias_domain FROM alias_domain WHERE alias_domain='%s' and active = '1'
Set proper permissions and ownership for these configuration files by issuing the following commands:
chmod o= /usr/local/etc/postfix/mysql_* chgrp postfix /usr/local/etc/postfix/mysql_*
Next, we'll create a user and group for mail handling. All virtual mailboxes will be stored under this user's home directory.
pw groupadd vmail -g 150 pw useradd vmail -g vmail -u 150 -d /home/vmail -m
Now create /etc/postfix/main.cf with the following contents Please be sure to replace "example.yourdomain.com" with the fully qualified domain name you used for your system mail name.
File: /usr/local/etc/postfix/main.cf
soft_bounce = no
smtpd_banner = $myhostname
biff = no
append_dot_mydomain = no
inet_interfaces = all
myhostname = example.yourdomain.com
myorigin = $myhostname
mydomain = yourdomain.com
mynetworks = 127.0.0.0/8
mynetworks_style = host
mydestination = $myhostname, localhost.$mydomain, localhost
alias_maps = $virtual_alias_maps
local_transport = local
transport_maps = proxy:mysql:$config_directory/mysql_transport.cf
debug_peer_level = 2
debugger_command =
PATH=/bin:/usr/bin:/usr/local/bin:/usr/X11R6/bin
ddd $daemon_directory/$process_name $process_id & sleep 5
html_directory = /usr/local/share/doc/postfix
disable_vrfy_command = yes
mailbox_size_limit = 0
owner_request_special = no
recipient_delimiter = +
home_mailbox = Maildir/
mail_owner = postfix
command_directory = /usr/local/sbin
daemon_directory = /usr/local/libexec/postfix
data_directory = /var/db/postfix
queue_directory = /var/spool/postfix
sendmail_path = /usr/local/sbin/sendmail
newaliases_path = /usr/local/bin/newaliases
mailq_path = /usr/local/bin/mailq
mail_spool_directory = /var/spool/mail
manpage_directory = /usr/local/man
setgid_group = maildrop
unknown_local_recipient_reject_code = 450
# Virtual Domains and Users
virtual_transport = virtual
virtual_alias_maps =
proxy:mysql:$config_directory/mysql_virtual_forwarders_maps.cf,
proxy:mysql:$config_directory/mysql_virtual_groups_maps.cf,
proxy:mysql:$config_directory/mysql_virtual_alias_domains_maps.cf
virtual_mailbox_domains = proxy:mysql:$config_directory/mysql_virtual_domains_maps.cf
virtual_mailbox_maps = proxy:mysql:$config_directory/mysql_virtual_mailbox_maps.cf
virtual_mailbox_limit_maps = proxy:mysql:$config_directory/mysql_virtual_mailbox_limit_maps.cf
virtual_mailbox_base = /home/vmail
relay_domains =
proxy:mysql:$config_directory/mysql_parking_domains_maps.cf,
proxy:mysql:$config_directory/mysql_alias_domains.maps.cf
proxy_read_maps = $local_recipient_maps $mydestination $virtual_alias_maps $virtual_mailbox_maps $virtual_mailbox_domains $relay_domains $virtual_mailbox_limit_maps $transport_maps
virtual_minimum_uid = 150
virtual_uid_maps = static:150
virtual_gid_maps = static:150
# Additional for quota support
virtual_mailbox_limit_override = yes
virtual_maildir_limit_message = Sorry, the user's mail quota has exceeded.
virtual_overquota_bounce = yes
# SMTP Authentication
smtpd_sasl_auth_enable = yes
smtpd_sasl_security_options = noanonymous
broken_sasl_auth_clients = yes
smtpd_sasl_authenticated_header = yes
smtpd_sasl_type = dovecot
smtpd_sasl_path = private/auth
# TLS/SSL
smtpd_use_tls = yes
smtpd_tls_auth_only = no
smtpd_tls_cert_file = /usr/local/etc/postfix/smtpd.cert
smtpd_tls_key_file = /usr/local/etc/postfix/smtpd.key
# Other Configurations
strict_rfc821_envelopes = yes
smtpd_soft_error_limit = 10
smtpd_hard_error_limit = 20
smtpd_data_restrictions = reject_unauth_pipelining, reject_multi_recipient_bounce
smtpd_etrn_restrictions = reject
smtpd_helo_required = yes
smtpd_recipient_limit = 25
#smtpd_sender_login_maps = mysql:$config_directory/mysql_sender_check.cf
smtpd_recipient_restrictions =
permit_mynetworks,
permit_sasl_authenticated,
reject_unauth_destination,
reject_invalid_hostname,
reject_unauth_pipelining,
reject_non_fqdn_sender,
reject_unknown_sender_domain,
reject_non_fqdn_recipient,
reject_unknown_recipient_domain,
permit
smtpd_sender_restrictions =
permit_mynetworks,
reject_unverified_sender,
#reject_sender_login_mismatch,
#reject_unauthenticated_sender_login_mismatch,
permit_sasl_authenticated,
reject_unauth_destination,
reject_non_fqdn_sender,
reject_unknown_sender_domain,
permit
This completes the configuration for Postfix. Next, you'll make an SSL certificate for the Postfix server that contains values appropriate for your organization.
Issue the following commands to create the SSL certificate
cd /usr/local/etc/postfix openssl req -new -outform PEM -out smtpd.cert -newkey rsa:2048 -nodes -keyout smtpd.key -keyform PEM -days 365 -x509
You will be asked to enter several values similar to the output shown below. Be sure to enter the fully qualified domain name you used for the system mailname in place of "example.yourdomain.com".
Country Name (2 letter code) [AU]:PK State or Province Name (full name) [Some-State]:Punjab Locality Name (eg, city) []:Lahore Organization Name (eg, company) [Internet Widgits Pty Ltd]:MyComapny Organizational Unit Name (eg, section) []:Email Services Common Name (eg, YOUR name) []:example.yourdomain.com Email Address []:[email protected]
Set proper permissions for the key file by issuing the following command:
chmod o= /usr/local/etc/postfix/smtpd.key
This completes SSL certificate creation for Postfix. Next, you'll need to configure Dovecot for imap service.
Replace the contents of the file with the following example, substituting your system's domain name for yourdomain.com.
File: /usr/local/etc/dovecot/dovecot.conf
auth_mechanisms = plain login
base_dir = /var/run/dovecot/
disable_plaintext_auth = no
first_valid_gid = 150
first_valid_uid = 150
last_valid_gid = 150
last_valid_uid = 150
log_path = /var/log/maillog
log_timestamp = %Y-%m-%d %H:%M:%S
auth_username_format = %Lu
mail_access_groups = mail
mail_location = maildir:~/Maildir
passdb {
args = /usr/local/etc/dovecot/dovecot-mysql.conf
driver = sql
}
protocols = imap
service auth {
unix_listener /var/spool/postfix/private/auth {
group = postfix
mode = 0660
user = postfix
}
}
service imap-login {
inet_listener imap {
address = *
port = 143
}
}
service pop3-login {
inet_listener pop3 {
address = *
port = 110
}
}
ssl = yes
ssl_cert = </usr/local/etc/postfix/smtpd.cert
ssl_key = </usr/local/etc/postfix/smtpd.key
userdb {
args = /usr/local/etc/dovecot/dovecot-mysql.conf
driver = sql
}
MySQL will be used to store password information, so /etc/dovecot/dovecot-mysql.conf must be edited. Replace the contents of the file with the following example, making sure to replace "vadmin_password" with your mail password.
File: /usr/local/etc/dovecot/dovecot-mysql.conf
driver = mysql
connect = host=localhost user=vadmin password=vadmin_password dbname=vmanager
default_pass_scheme = MD5-CRYPT
password_query = SELECT password FROM mailbox WHERE username = '%u'
user_query = SELECT '/home/vmail/%d/%n/Maildir' as home, 'maildir:/home/vmail/%d/%n/Maildir' as mail, 150 AS uid, 150 AS gid, concat('dirsize:storage=',quota) AS quota FROM mailbox WHERE username ='%u' AND active ='1'
Postfix and Dovecot has now been configured, add the following lines to /etc/rc.conf so that the Postfix and Dovecot will start automatically ast system boot.
echo 'postfix_enable="YES"' >> /etc/rc.conf echo 'dovecot_enable="YES"' >> /etc/rc.conf
You must restart Postfix and Dovecot to make sure both work properly.
service dovecot restart service postfix restart
Thats all Postfix and Dovecot installation is completed. Now let's install Apache and PHP for Postfix vManager Application.
To verify Postfix supports TLS, it has to be displaying STARTTLS when you connect to port 25 with telnet and run the EHLO command. We set this up in a previous step.
To verify the SSL certificate is working and Postfix can negotiate the SSL encryption you can use the openssl command.
openssl s_client -starttls smtp -crlf -connect mail.example.com:25
Substitute mail.example.com with the hostname of your mail server.
Apache is easily installed by entering the following command.
cd /usr/ports/www/apache22 make install clean
Once Apache has been successfully installed, add the following line to /etc/rc.conf so that the Apache server will start automatically at system boot.
echo 'apache22_enable="YES"' >> /etc/rc.conf
Configure Name-based Virtual Hosts
Now we will create virtual host entries for example.yourdomain.com site that we need to host with this server. Here is this.
File: /usr/local/etc/apache22/httpd.conf
NameVirtualHost *:80 <VirtualHost *:80> ServerAdmin [email protected] ServerName yourdomain.com ServerAlias example.yourdomain.com DocumentRoot /usr/local/www/vmanager ErrorLog /var/log/vmanager-error.log CustomLog /var/log/vmanager-access.log combined </VirtualHost>
Before you can use the above configuration you'll need to create the specified directories. For the above configuration, you can do this with the following commands:
mkdir /usr/local/www/vmanager
Postfix vManager depends on url rewriting for SEO purpose. In order to take advantage of this feature we need to edit httpd.conf file as follows.
Edit /usr/local/etc/apache22/httpd.conf file and change AllowOverride None to AllowOverride All under / directory e.g.
<Directory /> Options FollowSymLinks AllowOverride All </Directory>
We will therefore install PHP with the following command.
cd /usr/ports/lang/php5 make install cleean
A menu should come up allowing you to select/deselect various build options. You should select “Build Apache module” by highlighting the option with the arrow keys and hitting the space bar, then hit Enter.
After PHP installation we need add the requisite extensions to PHP for Postfix vManager.
cd /usr/ports/lang/php5-extensions/ make install clean
In the menu list you must select these extensions. Don't uncheck other selected options.
[ .. ] MBSTRING [ .. ] MYSQL [ .. ] MYSQLI [ .. ] PDO_MYSQL
Enable PHP into Apache
Now that we have the requisite ports built and installed it’s time to configure them.
Before going online with your site, you should consider copying /usr/local/etc/php.ini-production into php.ini
cp /usr/local/etc/php.ini-development /usr/local/etc/php.ini
Now enable php into apache, open the file /usr/local/etc/apache22/httpd.conf in your favorite editor and look for the following line:
DirectoryIndex index.html
And change it so it reads as follows:
DirectoryIndex index.html index.htm index.php
Then append the following lines to the end of the file in order to support PHP files as well as Postfix vManager
AddType application/x-httpd-php .php AddType application/x-httpd-php-source .phps
Here we need to restart apache server.
service apache22 restart
If everything has gone according to plan you should be able to open a browser and navigate to example.yourdomain.com
First download postfix vmanager source from this url :Source: https://app.box.com/s/lsz0b4w8cmu46qaz02w39far0djk1uny
After downloading the postfix-vmanager-2.0.tar.gz just extract the source.
Then first remove the /usr/local/www/vmanager directory and move extracted source into /usr/local/www/vmanager/ let's do it.
tar xzvpf postfix-vmanager-2.0.tar.gz rm -rf /usr/local/www/vmanager mv postfix-vmanager-2.0 /usr/local/www/vmanager
Next restore the database, with the following command
cd /usr/local/www/vmanager/ mysql -uroot -proot_pass vmanager < setup/vmanager.sql
Edit the inc/config.inc.php file and add your settings there. The most important settings are those for your database server.
$CONF['database_host'] = 'localhost'; $CONF['database_user'] = 'vadmin'; $CONF['database_password'] = 'vadmin_password'; $CONF['database_name'] = 'vmanager'; $CONF['database_port'] = '3306'; $CONF['database_prefix'] = '';
Postfix vManager require write access to its directory. So you need to change the vmanager directory ownership with that user as web server running.
chown -R www:www /usr/local/www/vmanager/
Hit :Source: https://example.yourdomain.com/ in a web browser. You should see a list of 'OK' messages. Otherwise reslove the issue if found.
Create the admin user using the form displayed. This is all that is needed.
The vacation script runs as service within Postfix's master.cf configuration file. Mail is sent to the vacation service via a transport table mapping. When users mark themselves as away on vacation, an alias is added to their account sending a copy of all mail to them to the vacation service.
To use vacation services you need to first create vacation domain. Just login as Super Admin account and then
Login as Super Admin and then create Vacation domain following this.
Go to Settings -> Vacation Domain.
There are a bunch of Perl modules which we need to install for Vacation setup.
cd /usr/ports/mail/p5-MIME-EncWords ; make install clean cd /usr/ports/mail/p5-Email-Valid ; make install clean cd /usr/ports/mail/p5-Email-Sender ; make install clean cd /usr/ports/mail/p5-Mail-Sender ; make install clean cd /usr/ports/devel/p5-Log-Log4perl ; make install clean cd /usr/ports/devel/p5-Log-Dispatch ; make install clean cd /usr/ports/databases/p5-DBI ; make install clean cd /usr/ports/databases/p5-DBD-mysql ; make install clean
Create Vacation Account:
Create a dedicated local user account called "vacation". This user handles all potentially dangerous mail content - that is why it should be a separate account.
Do not use "nobody", and most certainly do not use "root" or "postfix". The user will never log in, and can be given a "*" password and non-existent shell and home directory.
Create the user with the following command.
pw useradd vacation -c "Vacation Owner" -d /nonnonexistent -s /usr/bin/false
Create a directory:
Create a directory, for example /var/spool/vacation, that is accessible only to the "vacation" user. This is where the vacation script is supposed to store its temporary files.
mkdir /var/spool/vacation
Copy Files:
Copy the vacation.pl file to the directory you created above:
cp setup/vacation.pl /var/spool/vacation/vacation.pl chown -R vacation:vacation /var/spool/vacation/
Which will then look something like:
-rwx------ 1 vacation vacation 3356 Dec 21 00:00 vacation.pl*
Setup the transport type:
Define the transport type in the Postfix /etc/postfix/master.cf file:
vacation unix - n n - - pipe
flags=Rq user=vacation argv=/var/spool/vacation/vacation.pl -f ${sender} -- ${recipient}
Here we need to restart postfix service.
service postfix restart
Configure vacation.pl"
The perl /var/spool/vacation/vacation.pl script needs to know which database you are using, and also how to connect to the database.
Change any variables starting with '$db_' and '$db_type'
Change the $vacation_domain variable to match what you entered through your Super Admin login.
Here is the example of vacatino.pl settings for database and domain name
our $db_type = 'mysql'; our $db_host = 'localhost'; our $db_username = 'username'; our $db_password = 'password'; our $db_name = 'dbname'; our $vacation_domain = 'autoreply.yourdomain.com';
Done! When this is all in place you need to have a look at the Postfix vManager inc/config.inc.php. Here you need to enable Virtual Vacation for the site.
I’m going to show you how to run Postifx with OpenDKIM on a FreeBSD operating system.
Prepare the installation of OpenDKIM adding an opendkim user:
pw useradd -n opendkim -d /var/db/opendkim -g mail -m -s "/usr/sbin/nologin" -w no
Let’s start installing OpenDKIM.
cd /usr/ports/mail/opendkim make install clean
Then allow OpenDKIM starting at boot time and executing as opendkim user:
echo 'milteropendkim_enable="YES"' >> /etc/rc.conf echo 'milteropendkim_uid="opendkim"' >> /etc/rc.conf
Edit Postfix configuration file.
nano /usr/local/etc/postfix/main.cf
And instruct postfix to use dkim milter:
smtpd_milters = inet:127.0.0.1:8891 non_smtpd_milters = $smtpd_milters milter_default_action = accept
Create configuration file for OpenDKIM
nano /usr/local/etc/opendkim.conf
Feel free to use the following one slightly edited to work with yourdomain.com domain:
LogWhy yes Syslog yes SyslogSuccess yes Canonicalization relaxed/simple KeyTable /var/db/opendkim/KeyTable SigningTable /var/db/opendkim/SigningTable InternalHosts /var/db/opendkim/TrustedHosts Socket inet:8891@localhost ReportAddress root SendReports yes
Edit /var/db/opendkim/TrustedHosts
nano /var/db/opendkim/TrustedHosts
Add domains, hostnames and/or ip’s that should be handled by OpenDKIM. Don’t forget localhost.
127.0.0.1 localhost x.253.204.64 x.253.204.32/27
Generate keys
Now generate the keys: one will be used by opendkim to sign your messages and the other to be inserted in your dns zone:
mkdir -p /var/db/opendkim/yourdomain.com opendkim-genkey -D /var/db/opendkim/yourdomain.com/ -d yourdomain.com -s default
Here you need to move default.private to default
cd /var/db/opendkim/yourdomain.com/ mv default.private default chown opendkim:mail /var/db/opendkim/
Add domain to KeyTable /var/db/opendkim/KeyTable
default._domainkey.yourdomain.com yourdomain.com:default:/var/db/opendkim/yourdomain.com/default
Add domain to SigningTable /var/db/opendkim/SigningTable
yourdomain.com default._domainkey.yourdomain.com
Add to DKIM public key to DNS
Add an entry for the public key to the DNS server you are using for your domain. You find the public key here:
cat /var/db/opendkim/yourdomain.com/default.txt
The above output should be like.
default._domainkey IN TXT "v=DKIM1; g=*; k=rsa; p=MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQClJj0qvcQvX7ssbGNBqFCTt+Wrh9G15QIXkFPbspt4uUOthLR8yl56CKohRVFfQTjoZjrmxSYDD8ZfV4rnPUu5bz07w7hbL3X1N5rLOM7RTDWU0NrYzGNVS07H4XNUJQRifVULREEqqvjASX6ivp1AH+OvvKn9mQTaSTjviD2cdQIDAQAB"
Now test the key using an OpenDKIM utiliy:
opendkim-testkey -vvv -d yourdomain.com -s default -k /var/db/opendkim/default
The above command will verify your zone settings.
Now start both OpenDKIM and Postifix:
/usr/local/etc/rc.d/milter-opendkim start /usr/local/etc/rc.d/postfix restart
Look at the DKIM-signature, there it is.
Further check and analysis can be made also on the website http://www.brandonchecketts.com/emailtest.php