Installing OpenDKIM from source on CentOS 5.5 to sign and verify emails with Postfix
This guide assumes you have CentOS 5.5 installed, a working Postfix configuration and that you would like to sign mail for more than one domain. It was carried out with the following software versions:
- Postfix 2.3.3
- OpenDKIM 2.0.4
- Sendmail (sources) 8.13.8
- OpenSSL 0.9.8e
Important links:
Install other necessary software
# yum install sendmail-devel # yum install openssl-devel
If you want to know exactly where the files belonging to a package are (OpenDKIM’s compiler should find them automatically):
# rpm -ql sendmail-devel /usr/include/libmilter /usr/include/libmilter/mfapi.h /usr/include/libmilter/mfdef.h /usr/lib/libmilter.a /usr/lib/libsm.a /usr/lib/libsmutil.a
Installing OpenDKIM
Download then extract OpenDKIM. Change to the extracted direcotry and run configure, make and then, as root, make install
$ tar -xzvf opendkim-2.0.4.tar.gz $ cd opendkim $./configure $ make $ su - # make install
Hi Simon,
Thanks a lot for the great post this made it very easy to setup, the only thing confusing me at present and thats the
_adsp._domainkey.example.com IN TXT “dkim=unknown”
I’ve sent test emails to autorespond+dkim[at]dk.elandsys.com, and it comes back with
DKIM Signature validation: DKIM-Signature could not be verified DKIM Author Domain Signing Practices: no DNS record for _adsp._domainkey.accepted.co.uk
Do you have any idea on how to fix this, or what I might be missing?
Thanks
Hi Kevin, glad you found the post useful
It’s going to be hard for me to help you with out more info. Can I recommend you join the OpenDKIM mailing list. I’m there plus others who are even more qualified to help.
Try mailing check-auth at verifier.port25 dot com too, then mail all relevant info to the mailing list
My Simon, This was a simple mistake my end, I had not setup the adsp entry in the DNS correctly.
Cheers for following up, happy signing.
I used this to get DKIM up and going for our Marketing MTAs. Amazing work. I would say one thing that might answer someones random question. If you are signing lots of mail across a few MTAs do not use a DB for OpenDkim it will slow you down. WAY WAY down. Great work here tho.
Cheerio
Thanks for the tip