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Frequently Answered Questions

Log Messages

Unable to open /etc/sasldb2

No user_deny.db

IOERROR: opening /var/lib/imap/user_deny.db: No such file or directory

No authentication

TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits new) no authentication

Debug level information, can be ignored. You can reduce verbosity by setting debug: 0 in imapd.conf(5), or by not including debug messages on the mail facility in syslog.

Unable to setsocketopt

unable to setsocketopt(IP_TOS) service ptloader/unix: Operation not supported

Informational message issued on startup. Not critical.

Anti-Spam

No X-Spam Headers

Email Blocked Using zen.spamhaus.org

You are seeing the following in /var/log/maillog (line breaks added for legibility):

NOQUEUE: reject: RCPT from unknown[3.2.1.0]: 554 5.7.1 Service \
unavailable; Client host [3.2.1.0] blocked using zen.spamhaus.org; \
from=<something@domain.tld>

This message indicates your SMTP server, receiving a message from the Internet, has refused the message.

The sending host (at IP address 3.2.1.0) is blocked using a centralized, external service (spamhaus.org), that keeps track of hosts and networks on the Internet with a reputation of spamming.

For more information on this service, see http://www.spamhaus.org/zen/.

You will want to continue performing these checks, but just in case you do not want to, the relevant setting in Postfix is:

# postconf smtpd_sender_restrictions

It is the responsibility of the sending host to notify the original sender the message was not delivered.