Emails are not delivered: Recipient address rejected: User unknown in virtual mailbox

Symptoms

• Emails to the local mailbox ([email protected]) are not delivered;
• The following error can be found in the /var/log/maillog
in regards to affected mailbox:

  NOQUEUE: reject: RCPT from example1.com[203.0.113.2]: 550 5.1.1 <[email protected]>: Recipient address rejected: User unknown in virtual mailbox table; from=<[email protected]> to=<[email protected]> proto=ESMTP helo=<example1.com>

• Output of the following command is empty:

  # postmap -s /var/spool/postfix/plesk/vmailbox | grep [email protected]

Cause

Email address does not exist on the server.

Resolution

1. Log in to Plesk GUI
2. Create an recipient mailbox ([email protected]) at Domains > example.com > Email Addresses > Create Email Address:
   

Additional information

Mail to external mail service is delivered locally