use strict;
use warnings;
use Mail::Sendmail;

my $from = '"Company Surveys" <surveys@surveys.com>';
my $subject = 'Your Survey';

open LIST, "<mailinglist"
  or die "Cannot open mailing list: $!";

open MESSAGE, "<mailinglist-message"
  or die "Cannot open mailinglist message: $!";

my @message = <MESSAGE>;

my %mails = (
     From    => "$from",
     Subject => "$subject",
     Message => join "", @message,
);

while (<LIST>) {
       sendmail('To' => $_, %mails) or warn $Mail::Sendmail::error;
       print "Message has been sent to $_";
};

close LIST;
close MESSAGE;
print "All e-mails sent successfully.\n\n";
[download]

---

Update: while was a foreach, due to a bad coding mistake. Thanks Animator

---

mailinglist-message is something like:

Dear Potential Customer,


blah blah

From time to time, we would like to send you more surveys
and our newsletter.

We respect your privacy, therefore, if you wish to 
unsubscribe from our list, please reply, changing 
the Subject Line to: unsubscribe
[download]

mailinglist is something like:

ghenry@me.com
ghenry@me.org
gavin.henry@me.com
ghenry@me.co.uk
ghenry@me.uk
[download]

etc. etc.