How to debug warning: SASL authentication failure: could not verify password?

[paul at odysen.com]

I've been having an issue sending emails and have looked online for the past few weeks and while I have learned a lot I still haven't been able to resolve my issue.  Any help would be greatly appreciated.

I'm able to receive emails but I'm unable to send email. I do not understand why the log states 'password matches successfully' and 'Authenticated' then reports 'SASL authentication failure: could not verify password'.

Log partial:
Sep 22 03:03:07 example.com authdaemond: [ID 702911 mail.debug] received auth request, service=smtp, authtype=login
Sep 22 03:03:07 example.com authdaemond: [ID 702911 mail.debug] authshadow: trying this module
Sep 22 03:03:07 example.com authdaemond: [ID 702911 mail.debug] authshadow: sysusername=tester01-example, sysuserid=<null>, sysgroupid=1003, homedir=/home/example.com/homes/tester01, address=tester01-example, fullname=Tester, maildir=<null>, quota=<null>, options=<null>
Sep 22 03:03:07 example.com authdaemond: [ID 702911 mail.debug] authshadow: clearpasswd=<null>, passwd=x
Sep 22 03:03:07 example.com authdaemond: [ID 702911 mail.debug] password matches successfully
Sep 22 03:03:07 example.com authdaemond: [ID 702911 mail.info] Authenticated: sysusername=tester01-example, sysuserid=<null>, sysgroupid=1003, homedir=/home/example.com/homes/tester01, address=tester01-example, fullname=Tester, maildir=<null>, quota=<null>, options=<null>
Sep 22 03:03:07 example.com authdaemond: [ID 702911 mail.info] Authenticated: clearpasswd=hidden_clear_password, passwd=hidden_encrypted_password
Sep 22 03:03:07 example.com postfix/smtpd[16860]: [ID 947731 mail.warning] warning: SASL authentication failure: could not verify password

I've set my log levels to:
/opt/local/etc/postfix/main.cf
smtpd_tls_loglevel = 3

/opt/local/etc/authlib/authdaemonrc
DEBUG_LOGIN=7

/opt/local/etc/sasl2/smtpd.conf
log_level: 7

Why would it report it as 'password matches successfully' and 'Authenticated' then report 'SASL authentication failure: could not verify password'?