Any system that includes an SMTP server supporting mail relaying or delivery MUST support the reserved mailbox "postmaster" as a case-insensitive local name.
Edit local-recipients.js and change the value of the PostmasterAliasMapper.canonical
attribute.
For example if the local user, john@example.com, should receive mails sent to the postmaster addresses
then the result should look like this:
... setup(PostmasterAliasMapper, { canonical: "john@example.com" }), ...
The designated Postmaster will receive mails sent to the Postmaster of any local
domains (for example Postmaster@example.com)
and also to the special Postmaster (without domain) address.