Create a new alias for postfix service by updating the following file:

/etc/aliases

Each entry in the file must have the following syntax:

<ALIAS>: <USER1>[[, <USER2>], <USERn>]
Token Description
ALIAS The desired email alias.
USER1, USER2, USERn USER1 is required and the rest are optional. Each user must be delimited by a comma.

The target user of the alias must be a valid user of the system with a home directory.

Example:

postmaster: root

After updating the file, you must execute the following command:

sudo newaliases