Add Domain specific DKIM in PMTA config

#MTAs

<virtual-mta ip1>

    smtp-source-host 192.198.0.1 host.domain.tld

    <domain *>

        max-msg-rate 400/h

    </domain>

</virtual-mta>

#DKIM Keys

domain-key key1,domain1.tld,/etc/pmta/keys/key1.domain.tld

domain-key key2,domain2.tld,/etc/pmta/keys/key2.domain.tld

domain-key key3,domain3.tld,/etc/pmta/keys/key3.domain.tld

#Specify the DKIM for specific Domain using Directive

<domain domain1.tld>

    dkim-sign yes

    smtp-hosts [127.0.0.1]:587

    dkim-identity @domain1.tld

</domain>

<domain domain2.tld>

    dkim-sign yes

    smtp-hosts [127.0.0.1]:587

    dkim-identity @domain2.tld

</domain>

<domain domain3.tld>

    dkim-sign yes

    smtp-hosts [127.0.0.1]:587

    dkim-identity @domain3.tld

</domain>

#CALL PMTA POOL for Rotation

<virtual-mta-pool pmta-pool>

    virtual-mta ip1

</virtual-mta-pool>