2. Creating the Virtual Email user
All our emails will be handled by a unique system user on the system: vmail, postfix and dovecot will take care of handling authentication.
To create the vmail user proceed as follow:
groupadd -g 5000 vmail
useradd -g vmail -u 5000 vmail -d /var/vmail
mkdir /var/vmail
chown vmail:vmail /var/vmail
viaHow-To: Virtual emails accounts with Postfix and Dovecot | Debian/Ubuntu Tips & Tricks.