File: //usr/share/webmin/postfix/help/opt_sun_mailtool_compatibility.html
<header>Disable kernel file lock on mailboxes</header>
<center><tt>sun_mailtool_compatibility</tt></center>
<hr>
This parameter disables kernel file locks on mailboxes.
<p>
This is needed on SUN workstations because the <tt>mailtool</tt> program keeps
an exclusive kernel lock while its window is open. SUN software uses
<tt>user.lock</tt> files only. Unless you remove all SUN mail software, kernel
locks just give a false sense of security.
<hr>