- Plesk for Linux
Sending or forwarding an email to firstname.lastname@example.org fails:
CONFIG_TEXT: SMTP Error (550): Failed to add recipient "email@example.com" (5.1.1 <firstname.lastname@example.org>: Recipient address rejected: User unknown in virtual mailbox table)
CONFIG_TEXT: cannot chdir to mailname dir user: No such file or directory
Unknown user: email@example.com
NOQUEUE: reject: RCPT from localhost[::1]: 550 5.1.1 <firstname.lastname@example.org>: Recipient address rejected: User unknown in virtual mailbox table; from=<> to=<email@example.com> proto=ESMTP helo=
CONFIG_TEXT: Reason: The recipient does not exist
Message could not be delivered - the address was not found, is unknown, or is not receiving messages.
Domain example.com exists on a local Plesk server and on external server.
Domain resolves to globally to an external server (IP 203.0.113.2 is not present on a local Plesk server):
# dig +short example.com && dig +short mail.example.com
Plesk uses Posftfix mail server that performs local mail delivery without DNS queries. This way, sender domain tries to connect to a recipient domain example.com locally and it cannot find the mailbox firstname.lastname@example.org on a Plesk server, thus, message is rejected. Posftfix does not retry to deliver email to external server if recipient mailbox was not found locally: this is how Postfix works.
Disable mail service on example.com domain on a local Plesk server in Domains > example.com > Mail Settings >