I run saslfinger to get a better diagnostic, output is below and my humble knowledge can do much more with it.
I still haven't configured / recompiled postfix as I'm trying to make SASL work
saslfinger - postfix Cyrus sasl configuration Thu Apr 27 15:21:55 BST 2006
version: 1.0
mode: server-side SMTP AUTH
-- basics --
Postfix: 2.2.5
System: Red Hat Enterprise Linux ES release 3 (Taroon Update 5)
-- smtpd is linked to --
libsasl2.so.2
=> /usr/lib/libsasl2.so.2 (0x00f71000)
-- active SMTP AUTH and TLS parameters for smtpd --
broken_sasl_auth_clients = yes
-- listing of /usr/lib/sasl --
total 412
drwxr-xr-x 2 root root 4096 Apr 26 20:04 .
drwxr-xr-x 86 root root 40960 Dec 1 02:36 ..
-rw-r--r-- 1 root root 4560 Oct 7 2004 libanonymous.a
-rwxr-xr-x 1 root root 771 Oct 7 2004
libanonymous.la
-rwxr-xr-x 1 root root 5900 Oct 7 2004 libanonymous.so
-rwxr-xr-x 1 root root 5900 Oct 7 2004 libanonymous.so.1
-rwxr-xr-x 1 root root 5900 Oct 7 2004
libanonymous.so.1.0.17
-rw-r--r-- 1 root root 10688 Oct 7 2004 libcrammd5.a
-rwxr-xr-x 1 root root 757 Oct 7 2004 libcrammd5.la
-rwxr-xr-x 1 root root 10912 Oct 7 2004
libcrammd5.so
-rwxr-xr-x 1 root root 10912 Oct 7 2004 libcrammd5.so.1
-rwxr-xr-x 1 root root 10912 Oct 7 2004 libcrammd5.so.1.0.19
-rw-r--r-- 1 root root 35246 Oct 7 2004
libdigestmd5.a
-rwxr-xr-x 1 root root 780 Oct 7 2004 libdigestmd5.la
-rwxr-xr-x 1 root root 30724 Oct 7 2004 libdigestmd5.so
-rwxr-xr-x 1 root root 30724 Oct 7 2004
libdigestmd5.so.0
-rwxr-xr-x 1 root root 30724 Oct 7 2004 libdigestmd5.so.0.0.20
-rw-r--r-- 1 root root 12368 Oct 7 2004 libgssapiv2.a
-rwxr-xr-x 1 root root 806 Oct 7 2004
libgssapiv2.la
-rwxr-xr-x 1 root root 13004 Oct 7 2004 libgssapiv2.so
-rwxr-xr-x 1 root root 13004 Oct 7 2004 libgssapiv2.so.1
-rwxr-xr-x 1 root root 13004 Oct 7 2004
libgssapiv2.so.1.0.19
-rw-r--r-- 1 root root 7316 Oct 7 2004 liblogin.a
-rwxr-xr-x 1 root root 755 Oct 7 2004 liblogin.la
-rwxr-xr-x 1 root root 8144 Oct 7 2004
liblogin.so
-rwxr-xr-x 1 root root 8144 Oct 7 2004 liblogin.so.0
-rwxr-xr-x 1 root root 8144 Oct 7 2004 liblogin.so.0.0.7
-rw-r--r-- 1 root root 6864 Oct 7 2004
libplain.a
-rwxr-xr-x 1 root root 757 Oct 7 2004 libplain.la
-rwxr-xr-x 1 root root 7896 Oct 7 2004 libplain.so
-rwxr-xr-x 1 root root 7896 Oct 7 2004
libplain.so.1
-rwxr-xr-x 1 root root 7896 Oct 7 2004 libplain.so.1.0.16
-rw-r--r-- 1 root root 19 Jun 30 2004 Sendmail.conf
-- listing of /usr/lib/sasl2 --
total 684
drwxr-xr-x 2 root root 4096 Apr 27 14:41 .
drwxr-xr-x 86 root root 40960 Dec 1 02:36 ..
-rw-r--r-- 1 root root 13946 Oct 7 2004 libanonymous.a
-rwxr-xr-x 1 root root 780 Oct 7 2004
libanonymous.la
-rwxr-xr-x 1 root root 12204 Oct 7 2004 libanonymous.so
-rwxr-xr-x 1 root root 12204 Oct 7 2004 libanonymous.so.2
-rwxr-xr-x 1 root root 12204 Oct 7 2004
libanonymous.so.2.0.15
-rw-r--r-- 1 root root 17232 Oct 7 2004 libcrammd5.a
-rwxr-xr-x 1 root root 766 Oct 7 2004 libcrammd5.la
-rwxr-xr-x 1 root root 14880 Oct 7 2004
libcrammd5.so
-rwxr-xr-x 1 root root 14880 Oct 7 2004 libcrammd5.so.2
-rwxr-xr-x 1 root root 14880 Oct 7 2004 libcrammd5.so.2.0.15
-rw-r--r-- 1 root root 52730 Oct 7 2004
libdigestmd5.a
-rwxr-xr-x 1 root root 789 Oct 7 2004 libdigestmd5.la
-rwxr-xr-x 1 root root 42900 Oct 7 2004 libdigestmd5.so
-rwxr-xr-x 1 root root 42900 Oct 7 2004
libdigestmd5.so.2
-rwxr-xr-x 1 root root 42900 Oct 7 2004 libdigestmd5.so.2.0.15
-rw-r--r-- 1 root root 23282 Oct 7 2004 libgssapiv2.a
-rwxr-xr-x 1 root root 815 Oct 7 2004
libgssapiv2.la
-rwxr-xr-x 1 root root 20728 Oct 7 2004 libgssapiv2.so
-rwxr-xr-x 1 root root 20728 Oct 7 2004 libgssapiv2.so.2
-rwxr-xr-x 1 root root 20728 Oct 7 2004
libgssapiv2.so.2.0.15
-rw-r--r-- 1 root root 14356 Oct 7 2004 liblogin.a
-rwxr-xr-x 1 root root 752 Oct 7 2004 liblogin.la
-rwxr-xr-x 1 root root 12652 Oct 7 2004
liblogin.so
-rwxr-xr-x 1 root root 12652 Oct 7 2004 liblogin.so.2
-rwxr-xr-x 1 root root 12652 Oct 7 2004 liblogin.so.2.0.15
-rw-r--r-- 1 root root 14268 Oct 7 2004
libplain.a
-rwxr-xr-x 1 root root 752 Oct 7 2004 libplain.la
-rwxr-xr-x 1 root root 12592 Oct 7 2004 libplain.so
-rwxr-xr-x 1 root root 12592 Oct 7 2004
libplain.so.2
-rwxr-xr-x 1 root root 12592 Oct 7 2004 libplain.so.2.0.15
-rw-r--r-- 1 root root 19596 Oct 7 2004 libsasldb.a
-rwxr-xr-x 1 root root 791 Oct 7 2004
libsasldb.la
-rwxr-xr-x 1 root root 15348 Oct 7 2004 libsasldb.so
-rwxr-xr-x 1 root root 15348 Oct 7 2004 libsasldb.so.2
-rwxr-xr-x 1 root root 15348 Oct 7 2004
libsasldb.so.2.0.15
-rw-r--r-- 1 root root 503 Apr 27 14:41 sample.conf
drwxr-xr-x 6 root root 4096 Oct 27 00:36 sasl2
-rw-r--r-- 1 root root 503 Apr 27 14:41
smtpd.conf
-- listing of /usr/local/lib/sasl2 --
total 2116
drwxr-xr-x 2 root root 4096 Apr 26 18:18 .
drwxr-xr-x 3 root root 4096 Apr 26 16:36 ..
-rwxr-xr-x 1 root root 692 Apr 25 20:55
libanonymous.la
-rwxr-xr-x 1 root root 46147 Apr 25 20:55 libanonymous.so
-rwxr-xr-x 1 root root 46147 Apr 25 20:55 libanonymous.so.2
-rwxr-xr-x 1 root root 46147 Apr 25 20:55
libanonymous.so.2.0.21
-rwxr-xr-x 1 root root 680 Apr 26 16:36 libcrammd5.la
-rwxr-xr-x 1 root root 50879 Apr 26 16:36 libcrammd5.so
-rwxr-xr-x 1 root root 50879 Apr 26 16:36
libcrammd5.so.2
-rwxr-xr-x 1 root root 50879 Apr 26 16:36 libcrammd5.so.2.0.21
-rwxr-xr-x 1 root root 710 Apr 25 19:50 libdigestmd5.la
-rwxr-xr-x 1 root root 95447 Apr 25 19:50
libdigestmd5.so
-rwxr-xr-x 1 root root 95447 Apr 25 19:50 libdigestmd5.so.2
-rwxr-xr-x 1 root root 95447 Apr 25 19:50 libdigestmd5.so.2.0.21
-rwxr-xr-x 1 root root 676 Apr 26 16:36
liblogin.la
-rwxr-xr-x 1 root root 46927 Apr 26 16:36 liblogin.so
-rwxr-xr-x 1 root root 46927 Apr 26 16:36 liblogin.so.2
-rwxr-xr-x 1 root root 46927 Apr 26 16:36
liblogin.so.2.0.21
-rwxr-xr-x 1 root root 676 Apr 26 16:36 libplain.la
-rwxr-xr-x 1 root root 46765 Apr 26 16:36 libplain.so
-rwxr-xr-x 1 root root 46765 Apr 26 16:36
libplain.so.2
-rwxr-xr-x 1 root root 46761 Oct 27 00:36 libplain.so.2.0.19
-rwxr-xr-x 1 root root 46765 Apr 26 16:36 libplain.so.2.0.21
-rwxr-xr-x 1 root root 692 Apr 25 20:55
libsasldb.la
-rwxr-xr-x 1 root root 79195 Apr 25 20:55 libsasldb.so
-rwxr-xr-x 1 root root 79195 Apr 25 20:55 libsasldb.so.2
-rwxr-xr-x 1 root root 79187 Oct 27 00:36
libsasldb.so.2.0.19
-rwxr-xr-x 1 root root 79195 Apr 25 20:55 libsasldb.so.2.0.21
-rwxr-xr-x 1 root root 707 Apr 26 16:36 libsql.la
-rwxr-xr-x 1 root root 244896 Apr 26 16:36
libsql.so
-rwxr-xr-x 1 root root 244896 Apr 26 16:36 libsql.so.2
-rwxr-xr-x 1 root root 60240 Oct 27 00:36 libsql.so.2.0.19
-rwxr-xr-x 1 root root 244896 Apr 26 16:36
libsql.so.2.0.21
-- content of /usr/lib/sasl2/smtpd.conf --
# SASL application configuration file for SMTP AUTH used by Postfix
# Global parameter
log_level: 3
# Password verification service
pwcheck_method: auxprop
# SMTP AUTH mechanisms
mech_list: PLAIN LOGIN CRAM-MD5
# auxiliary plugin parameters -> mysql password backend
auxprop_plugin: sql
sql_engine: mysql
sql_hostname: localhost
sql_database: smtpauthdb
sql_user: --- replaced ---
sql_passwd: --- replaced ---
sql_select: SELECT %p FROM users WHERE username = '%u' AND userrealm = '%r' and auth = '1'
sql_usessl: no
-- active services in /etc/postfix/master.cf --
removed due to still not using sasl w/ postfix and to reduce message body
-- mechanisms on localhost --
