The Unofficial Plesk FAQ

• Mail Problems
  • Although I’m listed as a best-preference MX or A for that host
  • 553 sorry, that domain isn’t in my list of allowed rcpthosts (#5.7.1)
  • rblsmtpd: 1.2.3.4 pid 30325: 451 Blocked – see http://www.spamcop.net/bl.shtml?1.2.3.4

Mail Problems

Although I’m listed as a best-preference MX or A for that host

Problem:

Hi. This is the qmail-send program at server.example.com.
I'm afraid I wasn't able to deliver your message to the following addresses.
This is a permanent error; I've given up. Sorry it didn't work out.

<user@example.com>:
Sorry. Although I'm listed as a best-preference MX or A for that host,
it isn't in my control/locals file, so I don't treat it as local. (#5.4.6)

Solution:
Sometimes Plesk generates incorrect mail configuration,
try to disable and then enable domain mail service from Plesk.

553 sorry, that domain isn’t in my list of allowed rcpthosts (#5.7.1)

Problem:

Your message did not reach some or all of the intended recipients.
Subject: FW: test
Sent: 4/2/2009 12:05 PM

The following recipient(s) could not be reached:
'user@example.com' on 4/2/2009 12:05 PM
553 sorry, that domain isn't in my list of allowed rcpthosts (#5.7.1)

Solution:

The client is not authenticating itself to the server:

• Check that the client is authenticating itself to server (SMTP Auth or POP before SMTP)
• Check that your xinetd file for SMTP contains:
  env = SMTPAUTH=1

rblsmtpd: 1.2.3.4 pid 30325: 451 Blocked – see http://www.spamcop.net/bl.shtml?1.2.3.4

Problem:

Subject ‘Test subject’, Account: ‘Example Account’, Server: ‘mail.example.com’, Protocol: SMTP,
Server Response: ‘rblsmtpd: 1.2.3.4 pid 30325: 451 Blocked – see http://www.spamcop.net/bl.shtml?1.2.3.4’, Port: 25, Secure(SSL): No, Error Number: 0×800CCC60

Solution:

Configure alternative smtp port (ex: 1025) for RBL blacklisted clients.