pam_pgsql and sasl authentication

[dimon at intellinetinc.com]

I've setup PostgreSQl as a container for email accounts and installed and 
configured pam_pgsql
But when I'm trying to login as a test.user I'm getting these errors:

in var/log/auth.log
Mar 13 09:35:05 intellinet saslauthd[77076]: attempting to authenticate: 
test.user
Mar 13 09:35:05 intellinet saslauthd[77076]: received : user: 'test.user', 
pass: 'test.user'
Mar 13 09:35:05 intellinet saslauthd[77076]: query: SELECT password FROM email 
WHERE login='test.user'
Mar 13 09:35:05 intellinet saslauthd[77076]: user test.user authenticated.
Mar 13 09:35:05 intellinet saslauthd[77076]: DEBUG: auth_pam: pam_acct_mgmt 
failed: User not known to the underlying authentication module
Mar 13 09:35:05 intellinet saslauthd[77076]: AUTHFAIL: user=test.user 
service=imap realm= [PAM acct error]

and in /var/log/messages:
Mar 13 09:35:11 intellinet saslauthd[77078]: AUTHFAIL: user=test.user 
service=imap realm= [PAM acct error]
Mar 13 09:35:11 intellinet imapd[79912]: badlogin: intellinet.ab.ca
[139.142.54.38] plaintext test.user SASL(-13): authentication failure: 
checkpass failed

In my /etc/pam.conf I have:
imap            auth    required        pam_pgsql.so            try_first_pass
sieve           auth    required        pam_pgsql.so            try_first_pass
saslauthd       auth    required        pam_pgsql.so            try_first_pass

and I'm running saslauthd -a pam

The user seems to be authenticated first right, but then 
DEBUG: auth_pam: pam_acct_mgmt failed: User not known to the underlying 
authentication module
I don't know where it comes from :-(
If anyone could help me please!

Best regards,
Dmitry