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 };
}


##</code><code>##

C:\test>619685 data\data.txt
mail1-in.nyc.domain.com
    postfix/smtpd
        (5) warning: **** non-SMPT command from ****
        (2) warning: **** queue file size limit exceeded
        (2331) warning: ****: hostname **** verification failed: hostname nor servname provided, or not known
        (1) warning: ****: hostname docsis4-97 verification failed: hostname nor servname provided, or not known
        (13) warning: Illegal address syntax from **** in MAIL command: ****
        (2) warning: numeric hostname: ****
        (1) warning: valid_hostname: empty hostname
mail1-in.sfc.domain.com
    postfix/smtpd
        (3) warning: **** non-SMPT command from ****
        (1508) warning: ****: hostname **** verification failed: hostname nor servname provided, or not known
        (8) warning: Illegal address syntax from **** in MAIL command: ****
    sendmail
        (480) File descriptors missing on startup: stderr; Bad file descriptor
mail1-out.nyc.domain.com
    ntpd
        (169) sendto(****): Bad file descriptor
    postfix/smtp
        (2) warning: malformed domain name in resource data of MX record for ****:
        (32) warning: no MX host for **** has a valid address record
        (18) warning: numeric domain name in resource data of MX record for ****: ****
        (2) warning: valid_hostname: empty hostname
    postfix/smtpd
        (7) warning: Illegal address syntax from **** in MAIL command: ****
    sm-mta
        (2) **** SYSERR(root): ****. config error: mail loops back to me (MX problem?)
    syslog-ng
        (1) Changing permissions on special file /dev/console
mail2-in.nyc.domain.com
    postfix/smtpd
        (2) warning: **** non-SMPT command from ****
        (1494) warning: ****: hostname **** verification failed: hostname nor servname provided, or not known
        (1) warning: ****: hostname t147235 verification failed: hostname nor servname provided, or not known
        (14) warning: Illegal address syntax from **** in MAIL command: ****
        (1) warning: valid_hostname: empty hostname
mail2-in.sfc.domain.com
    postfix/smtpd
        (3) warning: **** non-SMPT command from ****
        (6) warning: **** queue file size limit exceeded
        (1716) warning: ****: hostname **** verification failed: hostname nor servname provided, or not known
        (9) warning: Illegal address syntax from **** in MAIL command: ****
        (3) warning: reject: ETRN ****... from ****[****]
        (1) warning: reject: ETRN [****]... from ****[****]
        (1) warning: valid_hostname: empty hostname
mail2-out.nyc.domain.com
    ntpd
        (168) sendto(****): Bad file descriptor
    postfix/smtp
        (2) warning: malformed domain name in resource data of MX record for ****:
        (25) warning: numeric domain name in resource data of MX record for ****: ****
        (2) warning: valid_hostname: empty hostname
    sm-mta
        (1) **** SYSERR(root): ****. config error: mail loops back to me (MX problem?)
    syslog-ng
        (1) Changing permissions on special file /dev/console
mail2-out.sfc.domain.com
    postfix/smtp
        (61) warning: malformed domain name in resource data of MX record for ****:
        (1) warning: no MX host for **** has a valid address record
        (61) warning: valid_hostname: empty hostname