EDIT LJF: Now Dkim and SPF are directly integrated in YunoHost 2.4
Hi,
Please note that :
- This is the revision 2 of this Work In Progress How-To
- Until this is natively integrated in YnH core apps, it will mean to that postfix conf will be blocked (or each time there is a change some configuration lines will need to be added to the end of /etc/postfix/main.cf)
- To be fully functionnal DKIM requires a modification of the DNS, which propagantion can take up to 24h
- CREDIT : This tutorial has been initially based on the DKMI section of : http://sealedabstract.com/code/nsa-proof-your-e-mail-in-2-hours/ from Drew Crawford
- CREDIT : This tutorial has been reviewed based on https://www.digitalocean.com/community/tutorials/how-to-install-and-configure-dkim-with-postfix-on-debian-wheezy from Popute Sebastian Armin
- Replace DOMAIN.TLD by your own domain name
Changes in rev 2 :
- Much easier to manage more than one DOMAIN.TLD (future proof)
- Updated configuration as it seemed that the previous one was based on old software
So, here is the thing :
- We start by installing the right software :
sudo aptitude install opendkim opendkim-tools
- Then we configure opendkim
sudo nano /etc/opendkim.conf
(Text to be placed in the text file: )
AutoRestart Yes
AutoRestartRate 10/1h
UMask 022
Syslog yes
SyslogSuccess Yes
LogWhy Yes
Canonicalization relaxed/simple
ExternalIgnoreList refile:/etc/opendkim/TrustedHosts
InternalHosts refile:/etc/opendkim/TrustedHosts
KeyTable refile:/etc/opendkim/KeyTable
SigningTable refile:/etc/opendkim/SigningTable
Mode sv
PidFile /var/run/opendkim/opendkim.pid
SignatureAlgorithm rsa-sha256
UserID opendkim:opendkim
Socket inet:8891@127.0.0.1
Selector mail
- Connect the milter to Postfix:
sudo nano /etc/default/opendkim
(Text to be placed in the text file: )
SOCKET=“inet:8891@localhost”
- Configure postfix to use this milter:
sudo nano /etc/postfix/main.cf
(Text to be placed AT THE END in the text file: )
milter_protocol = 2
milter_default_action = accept
smtpd_milters = inet:127.0.0.1:8891
non_smtpd_milters = inet:127.0.0.1:8891
- Create a directory structure that will hold the trusted hosts, key tables, signing tables and crypto keys:
sudo mkdir -pv /etc/opendkim/keys/DOMAIN.TLD
- Specify trusted hosts:
sudo nano /etc/opendkim/TrustedHosts
(Text to be placed in the text file: )
127.0.0.1
localhost
192.168.0.1/24
*.DOMAIN.TLD
- Create a key table:
sudo nano /etc/opendkim/KeyTable
(Text to be placed in the text file: Be very careful, it needs to be on a SINGLE LINE for each domain )
mail._domainkey.DOMAIN.TLD DOMAIN.TLD:mail:/etc/opendkim/keys/DOMAIN.TLD/mail.private
- Create a signing table:
sudo nano /etc/opendkim/SigningTable
(Text to be placed in the text file: )
*@DOMAIN.TLD mail._domainkey.DOMAIN.TLD
- Now we generate the keys !
sudo cd /etc/opendkim/keys/DOMAIN.TLD
sudo opendkim-genkey -s mail -d DOMAIN.TLD
- Output the DKIM DNS line to the terminal. Then, we install it on our DNS server. My ZONE file looks like this. (Be very careful with the formatting, the “p=…” needs to be in a single line.
cat mail.txt
mail._domainkey IN TXT “v=DKIM1; k=rsa; p=AAAKKUHGCSqGSIb3DQEBAQUAA4GNADCBiQKBgQDPFrBM54eXlZPXLJ7EFphiA8qGAcgu4lWuzhzxDDcIHcnA/fdklG2gol1B4r27p87rExxz9hZehJclaiqlaD8otWt8r/UdrAUYNLKNBFGHJ875467jstoAQAB” ; ----- DKIM key mail for DOMAIN.TLD
- And we don’t forget to put the right rights otherwise opendkim will get grumpy…
chown -Rv opendkim:opendkim /etc/opendkim*
-
And finally, we restart everything :
sudo service opendkim restart
sudo service postfix restart -
To test if it is all working well (don’t forget that the DNS propagation can take a bit of take…) you can simply send an email to check-auth@verifier.port25.com and a reply will be received. If everything works correctly you should see DKIM check: pass under Summary of Results.
)
