Symptoms
-
When sending an email from webmail, the following error message is shown:
PLESK_INFO: SMTP Error (535): Authentication failed.
-
The following error message appears in
/var/log/maillog
:postfix/smtpd[7538]: warning: unknown[203.0.113.2]: SASL login authentication failed: authentication failure
-
The saslauthd service is up and running on the server:
# service saslauthd status
…
Active: active (running) since …
Cause
The Postfix smtpd.conf
configuration file is corrupted.
Resolution
-
Connect to the Plesk server via SSH.
-
Open the
smtpd.conf
file in a text editor (in this example, we are using the vi editor) and edit the file as follows:-
on CentOS/RHEL-based distributions
# vi /usr/lib64/sasl2/smtpd.conf
pwcheck_method: auxprop saslauthd
auxprop_plugin: plesk
saslauthd_path: /var/spool/postfix/private/plesk_saslauthd
mech_list: DIGEST-MD5 CRAM-MD5 PLAIN LOGIN
sql_engine: intentionally disabled
log_level: 4 -
on Debian/Ubuntu-based distributions
# cat /etc/postfix/sasl/smtpd.conf
pwcheck_method: auxprop saslauthd
auxprop_plugin: plesk
saslauthd_path: /private/plesk_saslauthd
mech_list: DIGEST-MD5 CRAM-MD5 PLAIN LOGIN
sql_engine: intentionally disabled
log_level: 4
-
-
Save the changes and close the file.
-
Restart the saslauthd service:
# service saslauthd start