Quelltext der Seite NTACurrent en:Multiple Email Domains

== Overview ==
If your organisation has multiple email domains that need to receive emails compliant to NTA 7516, the following additional configuration steps are required:
* Each domain requires a corresponding DNS setup. The "ntamx" element of the NTA 7516 TXT records must contain the Cryptshare Mail Gateway host. See [https://wiki.cryptshare.com/display/C4NTAMB/.DNS+Setup+v1.1.0 DNS Setup] for details.
* The Cryptshare Mail Gateway needs to be configured to handle multiple domains for sending and receiving. These configuration steps are described below.
== Configuration Steps ==
=== Enable relaying for multiple domains ===
The listed commands use the domains "domain.com", "domain.nl" and "domain.org", which stand as examples for your own domains.
# Impersonate as root user:
 sudo su
# Specify all domains (including the one that you entered during the setup program) as destination domains (and subdomains thereof) the system will relay mail to:
 postconf -e "relay_domains = domain.com,domain.nl,domain.org"
# Reload the changed configuration:
 postfix reload
=== Using different DKIM keys per domain (optional) ===
These configuration steps are required only if you have separate DKIM keypairs for each domain. Again, the listed commands use the domains "domain.com", "domain.nl" and "domain.org", which stand as examples for your own domains.
# Impersonate as root user:
 sudo su
# Open the OpenDKIM configuration file '''/etc/opendkim.conf''' in an editor
# Disable the following lines by adding a "#" to the beginning:
 #Domain             ...
 #KeyFile            /etc/dkimkeys/dkim.key
 #Selector           ...
# Add the following lines:
 KeyTable                /etc/opendkim/KeyTable
 SigningTable            /etc/opendkim/SigningTable
# Copy the private keys of each domain's DKIM keypair to '''/etc/dkimkeys''', for example /etc/dkimkeys/domain.com.key, /etc/dkimkeys/domain.nl.key, and /etc/dkimkeys/domain.org.key.
# Create a file '''/etc/opendkim/KeyTable''' with the following line for each domain:
 <selector>._domainkey.<domain> <domain>:<selector>:<path to private key>
For example:
 nta7516feb2021._domainkey.domain.com domain.com:nta7516feb2021:/etc/dkimkeys/domain.com.key
 nta7516feb2021._domainkey.domain.nl domain.nl:nta7516feb2021:/etc/dkimkeys/domain.nl.key
 nta7516feb2021._domainkey.domain.org domain.org:nta7516feb2021:/etc/dkimkeys/domain.org.key
# Create a file '''/etc/opendkim/SigningTable''' with the following line for each domain:
 <domain> <selector>._domainkey.<domain>
For example:
 domain.com nta7516feb2021._domainkey.domain.com
 domain.nl nta7516feb2021._domainkey.domain.nl
 domain.org nta7516feb2021._domainkey.domain.org
# Restart OpenDKIM:
 systemctl restart opendkim