I added a signing feature to my DKIM plugin.
https://github.com/qpsmtpd-dev/qpsmtpd-dev/blob/master/plugins/dkim
Matt
PS: for added pleasure, I also added a script that makes deploying DKIM really,
really easy. How easy?
# cd ~smtpd/config/dkim
# ./dkim_key_gen.sh example.org
Voila. Keys and selector generated. Now DNS needs to be updated. I made that
easy too:
# cat example.org/dns
apr2013._domainkey TXT
"v=DKIM1;p=MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEAt/Wu1fd74UXwH//0uiX/6C0hkv3I/PdeTxfnzHN6GrehJpCYBd1BKuigduwt/wZFVgUopwxmcjxSK6qrkADtHC+ZiqC/sqcVuVDhnvzkIgd7dYhqBcVORg6f8Eg8132yPkmHyDm588qKfdFSEUVgBqSfqZg4ZdG4Uq5erHAyQIEcs0h7xqUKJKA5xJWdRwaVYbNkNDAscax1WrSvMHQkKBf5bWUtkMGc/HeoZ6T3VTn5Le0OgLoINj4lNTFfT6toXsbZsKzOaUYacnWVOq2v2lWgghOMRQHYPr7ldl2E7/6sNSpNT8KXAiT7wlfE+/xXg+0DyQq/ahKaPgAecCCFiwIDAQAB"
Tell the world that the ONLY mail servers that send mail from this domain are
DKIM signed and/or bear our MX and A records.
With SPF:
SPF "v=spf1 mx a -all"
TXT "v=spf1 mx a -all"
With DMARC:
_dmarc TXT "v=DMARC1; p=reject; adkim=s; aspf=r;
rua=mailto:dmarc-feedb...@example.org; ruf=mailto:dmarc-feedback@'example.org;
pct=100"
With DomainKeys (deprecated)
_domainkey TXT "o=-; t=y; r=postmas...@example.org"
For more information about DKIM and SPF policy, the documentation within each
plugin contains a longer discussion and links to more detailed information:
perldoc plugins/dkim
perldoc plugins/sender_permitted_from
