[root@as etc]# cat /usr/lib/sasl2/smtpd.conf
pwcheck_method: saslauthd
>> PRODUCES THESE ERRORS <<
May 24 19:51:18 as postfix/smtpd[11709]: connect from [my ip]
May 24 19:51:21 as postfix/smtpd[11709]: warning: SASL authentication problem: unable to open Berkeley db /etc/sasldb2: No such file or directory
May 24 19:51:21 as postfix/smtpd[11709]: warning: SASL authentication problem: unable to open Berkeley db /etc/sasldb2: No such file or directory
May 24 19:51:21 as postfix/smtpd[11709]: warning: SASL authentication failure: no secret in database
May 24 19:51:21 as postfix/smtpd[11709]: warning: [my ip]: SASL CRAM-MD5 authentication failed
May 24 19:51:23 as postfix/smtpd[11709]: lost connection after AUTH from [my ip]
May 24 19:51:23 as postfix/smtpd[11709]: disconnect from [my ip]

-----------------------------------

[root@as etc]# cat /usr/lib/sasl2/smtpd.conf
pwcheck_method: saslauthd
mech_list: login plain

>> PRODUCES THESE ERRORS <<
May 24 19:53:24 as postfix/smtpd[11891]: warning: dict_nis_init: NIS domain name not set - NIS lookups disabled
May 24 19:53:24 as postfix/smtpd[11891]: fatal: no SASL authentication mechanisms
May 24 19:53:25 as postfix/master[5929]: warning: process /usr/libexec/postfix/smtpd pid 11891 exit status 1
May 24 19:53:25 as postfix/master[5929]: warning: /usr/libexec/postfix/smtpd: bad command startup -- throttling