Here is another approach that will count the numbers of digits in a given string.

use strict;
use warnings;

my @count;
my $i = 0;

while ( my $string = (<DATA>) ) {
    $string =~ s/(\D+)//g;
    push @count, split( //, $string );
}

for (@count) {
    ++$i;
    if ( $i >= 7 ) {
        print "\n7 or more so send to stop_spam() routine\n";
        exit;
    }
}

__DATA__
Title: !! back!! 7073347120 FREE VaShiKaRaN SpeCiaLisT IN Allahabad
Post: 707334712070733471207073347120707334712070733471207073347120
[download]