while( <> ) {
    next if /^\s*$/;        ## Skip blank lines
    my( $src, $mode, $rest ) =  m'
        ( ^ \S+ ) \s+ - \s+
        ( [^\[:]+ ) (?: \[ \d+ \] )? : \s*
        ( .+ $  )
    'x;
    if( $rest =~ m[warning: (?=.*Illegal address syntax)] ) {
        ++$log{ $src }{ $mode }{ 'warning: Illegal address syntax from **** in MAIL command: ****' };
        next;
    }
    if( $rest =~ m[warning: (?=.*non-SMTP command)] ) {
        ++$log{ $src }{ $mode }{ 'warning: **** non-SMPT command from ****' };
        next;
    }
    $rest =~ s[ (?: [\w-]+ \. ){1,} [\w-]+][****]gx;    ## Remove fqdns
    $rest =~ s[ [a-z] \w+ \d : ][****]gx;               ## Server names?
    $rest =~ s[ [A-Z0-9]{11} : ][****]x;                ## Queue names
    $rest =~ s[ < [^>]+ > ][****]x;                     ## Common form of bad name

    ++$log{ $src }{ $mode }{ $rest };
}