I stuck with not starting saslauthd service after upgrade Ubuntu to 24.04 (it runs along with Virutalmin). So i can’t authenticate to smtp (cant send mails, but still can recieve) due to error:
454 4.7.0 Temporary authetnitaction failure: generic failiure

I was trying to run saslauthd service by (systemctl status saslauthd shows service as: inactive (dead)):
systemctl start saslauthd
ends with timed out:

Job for saslauthd.service failed because a timeout was exceeded.
See "systemctl status saslauthd.service" and "journalctl -xeu saslauthd.service" for details.

during the start process – its create some files in /var/spool/postfix/var/run/saslauthd but after it ends with time out – directory its again empty.

I managed to run saslauthd by command bellow:
/usr/sbin/saslauthd -a pam -c -m /var/spool/postfix/var/run/saslauthd -r -n 5
and authorization started to work – tested with command bellow (also desktop client works):

nc localhost 25
220 ################ ESMTP Postfix (Ubuntu)
AUTH LOGIN
334 VXNlcm5hbWU6
######
334 UGFzc3dvcmQ6
######
235 2.7.0 Authentication successful

Envoirnment:

postfix 3.8.6
saslauthd 2.1.28
Ubuntu 24.04

Postfix 3.8.6 smtp config
/etc/postfix/master.cf:
smtp inet n - y - - smtpd -o smtpd_sasl_auth_enable=yes -o smtpd_tls_security_level=may

smtps inet n - y - - smtpd -o smtpd_sasl_auth_enable=yes -o smtpd_tls_security_level=may -o smtpd_tls_wrappermode=yes

saslauthd 2.1.28 config
/etc/default/saslauthd (remove commented lines)

START=yes

DESC="SASL Authentication Daemon"

NAME="saslauthd"

MECHANISMS="pam"

OPTIONS="-c -m /var/spool/postfix/var/run/saslauthd -r"

THREADS=5

OPTIONS="-c -m /var/spool/postfix/var/run/saslauthd -r"
PARAMS="-m /var/spool/postfix/var/run/saslauthd -r"