I know how to do all the counting and resetting stuff. Does anyone know how to make the script look like a sendmail like program as far as PHP’s mail functions are concerned?

Ah, I see, you're basically asking how to make the interface to your queuing system, which is basically:

* Keep a count of how many messages go out in x amount of time,

* Queue up messages that can't go out after the limit has been reached

* Reset counter after x amount

* Send awaiting messages,

* etc,

I've always used Getopt::Long for command line interfaces. To emulate what you'd give to sendmail, you'd do something like:

#!/usr/bin/perl 

use Getopt::Long; 


my $sendmail = '/usr/sbin/sendmail'; 


my $f_flag = undef; 
my $t_flag = undef; 
my $i_flag = undef; 
my $o_flag = undef; 


GetOptions("f=s"       => \$f_flag, 
           "t"         => \$t_flag, 
           "i"         => \$i_flag, 
           "o"         => \$o_flag, 
        );         

# Skipping the queue/count stuff for laziness...

my $sendmail_w_flags = $sendmail; 

if($f_flag){ 

    $sendmail_w_flags .= ' -f'.$f_flag;
}

if($t_flag){ 

    $sendmail_w_flags .= ' -t';;
}

if($i_flag){ 

    $sendmail_w_flags .= ' -i';;
}

if($o_flag){ 

    $sendmail_w_flags .= ' -o';;
}




my $message = <STDIN>; 

open(MAIL, '|' . $sendmail_w_flags) or die $!; 
print MAIL $message or die $!;
close MAIL or die $!;
[download]

(untested)