- Plesk for Linux
- Unable to send email from one domain hosted on Plesk to another domain (email@example.com) hosted on Plesk:
CONFIG_TEXT: SMTP Error (550): Failed to add recipient "firstname.lastname@example.org" (5.1.1 <email@example.com>: Recipient address rejected: User unknown in virtual mailbox table)
CONFIG_TEXT: cannot chdir to mailname dir user: No such file or directory
Unknown user: firstname.lastname@example.org
NOQUEUE: reject: RCPT from localhost[::1]: 550 5.1.1 <email@example.com>: Recipient address rejected: User unknown in virtual mailbox table; from=<> to=<firstname.lastname@example.org> 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.
CONFIG_TEXT: postfix/smtp: F1CE869AC4: to=<email@example.com>, relay=mail.example.com[203.0.113.2]:25, delay=42, delays=0.1/0.01/22/20, dsn=5.0.0, status=bounced (host mail.example.com[203.0.113.2] said: 550-Verification failed for <firstname.lastname@example.org> 550-No Such User Here 550 Sender verify failed (in reply to RCPT TO command))
- example.com exists in Plesk but it's mail service is handled on external server (it uses third-party mail service):
# dig MX example.com
example.com. 299 IN MX 5 alt1.aspmx.l.google.com.
example.com. 299 IN MX 10 alt3.aspmx.l.google.com.
example.com. 299 IN MX 10 alt4.aspmx.l.google.com.
example.com. 299 IN MX 1 aspmx.l.google.com.
example.com. 299 IN MX 5 alt2.aspmx.l.google.com.
- The following bounce-back email may be delivered to the sender:
CONFIG_TEXT: Action: failed
Diagnostic-Code: x-unix; No Such User Here
Postfix mail server always trying to deliver a message locally first. Since example.com exists on a local server, Postfix is looking for a mailbox email@example.com locally without checking domain's external mail service. Postfix does not retry to deliver email to the external server if recipient mailbox was not found locally: this is Postfix's behavior by design.
Disable mail service for recipient domain. It has mail served externally anyway, so by disabling mail service on a Plesk server for example.com, Postfix will not check for firstname.lastname@example.org mailbox presence locally and will connect to external mail server directly using global DNS records:
- Login to Plesk
- Disable mail service in Plesk: Domains > example.com > Mail Settings > uncheck option Activate mail service on this domain: