[Exim] Authentication problem.

Hello.

I have problems with my exim, because all authenticate users can use
other logins and domains.
Example:

user with login: somebody is authenticate as somebody and he can send
email as root@???

authenticate user can send email as somebody@???


My configuration:

# MAIN CONFIGURATION SETTINGS
acl_smtp_auth = acl_check_auth

# ACL CONFIGURATION
acl_check_auth:
accept encrypted = *
accept condition = ${if \
    eq {${substr_0_5:$smtp_command_argument}}{PLAIN}{yes}{no}}
accept condition = ${if \
    eq {${substr_0_8:$smtp_command_argument}}{LOGIN}{yes}{no}}

should i send full config. file?