Exim/DKIM

DomainKeys Identified Mail (DKIM) is an email authentication method designed to detect email spoofing.

Initial Setup

• Create an empty file at /etc/exim4/dkim_domains
• Edit /etc/exim4/conf.d/main/00_local_settings and add

  DKIM_DOMAIN =      ${lookup{$sender_address_domain}lsearch*@{/etc/exim4/dkim_domains}{$sender_address_domain}{}}
  DKIM_SELECTOR =    ${extract{selector}{${lookup{$sender_address_domain}lsearch*@{/etc/exim4/dkim_domains}}}{$value}{}}
  DKIM_PRIVATE_KEY = ${extract{key}{${lookup{$sender_address_domain}lsearch*@{/etc/exim4/dkim_domains}}}{$value}{}}
  DKIM_CANON =       ${extract{canon}{${lookup{$sender_address_domain}lsearch*@{/etc/exim4/dkim_domains}}}{$value}{relaxed}}
  DKIM_STRICT =      ${extract{strict}{${lookup{$sender_address_domain}lsearch*@{/etc/exim4/dkim_domains}}}{$value}{false}}