Show username when there is SASL authentication failure

I’m using virtualmin with postfix and cyrus-sasl.

When ever there is an authentication failure it reports in /var/log/maillog below line.

postfix/smtpd[27669]: warning: unknown[185.xxx.xxx.xxx]: SASL LOGIN authentication failed: authentication failure

How can I make it so that it will also report the username that failed in the log file ( like SASL LOGIN authentication failed: authentication failure for alice )?

IF the user name exists on the system, it will show it. If an unknown user name is input, it shows “unknown” right before the IP.

“unknown” is the reverse lookup for the IP.

If there is a PTR set for that IP, then it will show like

warning: srv123454.hostname.com[xxx.xxx.xxx.xxx]: SASL LOGIN authentication failed: authentication failure

any one?