Setup dkim on postfix

Get the latest tutorials on SysAdmin and open source topics. Hollie's Hub for Good Supporting each other to make an impact. Write for DigitalOcean You get paid, we donate to tech non-profits. The frustration of getting falsely flagged as a spammer is not strange to most of the mail server admins.

By excluding the possibility of a compromised server, a false flag is usually caused by one of the following:. These are some of the basic properties that are being checked by the majority of proprietary and open source spam filters including SpamAssassin. Passing these tests is extremely important for a well configured mail server. It is assumed that the reader knows how to access the server over SSH, Postfix and Dovecot is already installed and configured tutorial , the host name and the FQDN are set up tutorial , tutorial and the SPF record is in place tutorial.

DKIM is an Internet Standard that enables a person or organisation to associate a domain name with an email message. This, in effect, serves as a method of claiming responsibility for a message. At its core, DKIM is powered by asymmetric cryptography.

Additional packages will be listed as dependencies, type yes and press Enter to continue. Important: replace every instance of example. Append the following lines to the end of the conf file each parameter is explained below.

Optionally, you can choose a custom port number for the Socket. UMask : gives all access permissions to the user group defined by UserID and allows other users to read and execute files, in this case it will allow the creation and modification of a Pid file. In case of a tcp socket, for selinux , the following command will need to be executed as the superuser, which declares the chosen port to be a milter application port:. It's a file that maps key names to signing keys.

If you wish to sign mail that comes from sources other than the localhost address Email - Postfix. With the OpenDkim Socket configuration of this tutorial the default. If the test does not work, check the diagnostic section. The first easy method to test is to send an email to the mail-tester website. They will then analyze it and give you a score. Marketing Advertising Analytics Email. Contact [email protected] Privacy Policy Status.

Start Marketing Email Postfix. Generate the key and the DNS record with opendkim-genkey. Generate a private and public key pair to sign the mail skipped if you will only be verifying. Post the public key in the DNS space also skipped if only verifying. Configure the mail transfer agent MAT ie Postfix.

To maintain consistency between sender and recipient addresses, myorigin also specifies the default domain name that is appended to recipient addresses that have no domain part. We will use the default setting.

This variable sets all domains we would accept mail to. That is basically all the initial configuration we need: it tells the smtpd to listen to 25 port on all interfaces, accept mail to andreybondarenko. The last thing we need to do is to tell Systemd to start Postfix on boot and to run it now:.

In fact, the only thing that Domain Key technology provides is the information that the person who controls the DNS also controls the mail server. Check those permissions are following for the private key only opendkim user can read :.

The first file defines where to look for the private key for the domain remember that real life server can have many of them and second defines that all mail should be signed with this key.

TrustedHosts is trivial and default:. Last part at the host is to tell the Postfix to forward all mail to the opendkim first by adding local milter :. Now the last and very important part: we need to the public the open part of the key to the world with the DNS TXT record.