Postfix

DKIM with OpenDKIM

Create new signing key

   opendkim-genkey -D /var/db/dkim -d conti.work -s mail

Add domain to /var/db/dkim/opendkim-signingingtable

   conti.work mail._domainkey.conti.work

Add key to /var/db/dkim/opendkim-keytable

   mail._domainkey.conti.work conti.work:mail:/var/db/dkim/mail.private

Add TXT record to DNS

   cat /var/db/dkim/mail.txt
   
   mail._domainkey IN      TXT     ( "v=DKIM1; k=rsa; "
             "p=MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQDeKDcrLhvbX0DoeRuX5b9gx84jyU4oBgMIzf1n4VSo4NUQOEjP63rwGZd4sAsSbm7tcNoc7sUtoj7k7euC9H6xvSCYyewxva7FdJuBH6gbHvMJbl5k9pXnWvDUsovYRHTqXqWL0Ecf8ic9K+vLlCLVac9+3aS31djobJt2CVqeRwIDAQAB" )  ; ----- DKIM key mail for conti.work

Disable CatchAll for certain addresses

Although catch all is active some addresses can be disabled by adding

      check_recipient_access hash:/etc/postfix/access,

to the smtp_recipient_restrictions . Access file has

   rejected@riechers.info REJECT

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