Next to the official Nethserver documentation, various tips and tricks are mentioned in the user forums. This page tries to catch these here. Use at your own risk.

Multidomains (Multitennancy) is possible wih NethServer, at least for mail…

I'll be using a typical environment for SME environments: a primary domain (The one your NethServer is probably using), and two secondary mail domains. These Domains will be called:

• domain1.com (Primary Domain)
• domain2.com (1st secondary Domain)
• domain3.com (2st secondary Domain)

Add in additional maildomains in NethServers Cockpit under Email → Domains

and

For all additional Domains, you’ll need external DNS entries (mail.domain2.tld) for the maildomain and Mailserver, but also MX entries and needewd stuff for DKIM, SPF etc. Use your primary maildomain as example. The primary domain should be used for all three maildomains in the DNS SPF entry.

Additional attention will be needed to take correct care SMTP helo acceptance, as we have three domains, but only one server awnsering. The same goes for PTR, which should point to mail.domain1.com, your primary maildomain hostname.

These additional maildomains will generally allow in and outgoing mail, as for all Maildomains. To stop incoming, you can redirect all the incoming to a noreply kind of account, set a mail rule to reply accordingly.

As all “incomng” for these “special” accounts are directed to a single mail account (Mailbox), it should be easy to set up a rule to clean this folder up…

Create the users for these domains as following:

• user1_domain1@domain1.com
• user2_domain1@domain1.com
• info_domain1@domain1.com (Alias info@domain1.com )
• sales_domain1@domain1.com (Alias sales@domain1.com )
• support_domain1@domain1.com (Alias support@domain1.com )

• user1_domain2@domain2.com
• user2_domain2@domain2.com
• info_domain2@domain2.com (Alias info@domain2.com )
• sales_domain2@domain2.com (Alias sales@domain2.com )
• support_domain2@domain2.com (Alias support@domain2.com )

• user1_domain3@domain3.com
• user2_domain3@domain3.com
• info_domain3@domain3.com (Alias info@domain3.com )
• sales_domain3@domain3.com (Alias sales@domain3.com )
• support_domain3@domain3.com (Alias support@domain3.com )

Adapt the users as needed.
Use the Address option to set the correct external addresses.

(sources: User forums)