How do I send an email using sendmail?

# Open a stream, piped to your sendmail program. You
# should send the process to the background and send all
# output to /dev/null so that your program does not hang
# if the mail queue takes awhile
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open (MAIL, "| /usr/sbin/sendmail -t >& /dev/null");
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# Print the To: field to your mail stream. You can either
# enter the recipient email by itself, or in the standard
# format of Name <address>
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print MAIL qq~To: "$title" <$email_addr>\n~;
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# If you want to send to a list, send the mail only once,
# but make each address a blind carbon copy.
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print MAIL qq~Bcc: ~;
my $address = pop(@LIST);
print MAIL qq~$address~;
foreach $address (@LIST) {print MAIL qq~, $address~;}
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# Include the remaining header info
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print MAIL qq~\nFrom: "$return_name" <$return_addr>\n~;
print MAIL qq~Reply-To: $return_addr\n~;
print MAIL qq~List-Unsubscribe: $return_addr\n~;
print MAIL qq~Subject: $subject\n~;
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# To send HTML formatted emails, your Content-Type needs
# to be text/html. Otherwise it is text/plain. This being
# the last line before the body, there are two newlines at
# the end of this line.
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print MAIL qq~Content-Type: text/plain\n\n~;
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# Then, print the body of your email to the mail stream
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print MAIL qq~$body_text\n~;
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# And close with a period on a line of its own. This is
# not necessary, since the mail will send when you close
# the stream, but it is the correct sendmail format.
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print MAIL qq~.~;
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# Close your mail stream, and your email will be sent to
# the sendmail queue to be sent out. Sendmail will figure
# out the best way of doing this for you. If you have a
# large list, it may send a few emails every few minutes.
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close(MAIL);
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