How to setup same DKIM setings for multiple servers

dkimpostfix

I have three servers configured to relay mail. I am using dkim-milter with postfix on CentOS 5.5. I created domain keys on the command line for each server. My issue is that the domain key is different for each server, and I have to setup different DNS records for each relay server.

How can I setup a single key for all servers in TXT records?

Best Answer

Just use the same key for all the servers, and tell them to use the same DKIM identifier for all of them. How exactly you'll do that depends on how you set it up, but having generated and installed the keys, working out how to make them all the same should be relatively easy.

Related Solutions

Signing multiple domains with dk-milter

I finally managed to do it.

I installed dk-milter using 1.0.2 rpm that I found. Then I followed the steps described here http://www.tai.ro/2010/04/03/postfix-with-dkim-domainkeys-spf-and-sender-id/ and I created this configuration for dk-milter:

USER="opendkim-milt"
PORT="inet:10035@localhost"
SIGNING_DOMAIN="/etc/mail/dkim/trusted-hosts"
SELECTOR_NAME="default"
KEYFILE="/etc/mail/domainkeys/keylist"
SIGNER=yes
VERIFIER=yes
CANON=simple
REJECTION="bad=r,dns=t,int=t,no=a,miss=r"
EXTRA_ARGS="-h -l -D -k -i /etc/mail/dkim/trusted-hosts"
SYSCONFIG="/etc/sysconfig/dk-milter"
MILTER_GROUP="opendkim-milt"

This is the same in /etc/init.d/dk-milter and /etc/syconfig/dk-milter I used the same user as for opendkim just so that I can read the files directly from dkim directory (the directory must have 700 in orver for the keys to be considered valid)

The only file I have left in the domainkeys directory is keylist that contains rows like this: *@domain.tld:/var/db/domainkeys/domain.tld/default. And I will probably move this to the dkim directory so that I only use that one.

Now when I need to add a domain I need to follow the next steps: 1. add the directory domain.tld in /etc/mail/dkim/keys/ and generate the keys in that directory then change their owner to opendkim-milt like decribed in the tutorial for dkim 2. add the corresponding lines to /etc/mail/dkim/keyTable signingTable trusted-hosts and /etc/mail/domainkeys/keylist 3. add the public domain key to the DNS entry (from default.txt) and modify it so that it's used for both (just let "k=rsa ; p=...") 4. restart opendkim, dk-milter and postfix services

Everything works great now. Thanks

Centos – How to install dkim for postfix in centos 5.4

I have had good success using DKIMProxy. Check out this article: http://www.brandonchecketts.com/archives/getting-dkimproxy-installed-and-configured

And in your comments to @mattdm you are confusing SPF with DKIM-Signature. Both use DNS TXT records but they are separate things/records. With some Registrars/DNS Providers you need to turn on "Advanced DNS Records" or similar description in order to create TXT records.

You basically publish the public part of your key in the TXT record for DKIM-Signature.

HTH

Cheers

Best Answer

Related Solutions

Signing multiple domains with dk-milter

Centos – How to install dkim for postfix in centos 5.4

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