Try in the Template Toolkit USE Dumper; Dump ( $content ); Your code:

    $template_1->process($template_file, $vars)
    || die "Template process failed: ", $template->error(), "\n";

    &send_mail_html($email, $from_address, $subject, $template_1);

    $template_file = 'confirm_contact_info_email.htm';

    $template->process($template_file, $vars)
    || die "Template process failed: ", $template->error(), "\n";
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This is what process is supposed to do, from docs:

By default, the processed template output is printed to STDOUT. The process() method then returns 1 to indicate success. A third parameter may be passed to the process() method to specify a different output location. This value may be one of: a plain string indicating a filename which will be opened (relative to OUTPUT_PATH, if defined) and the output written to; a file GLOB opened ready for output; a reference to a scalar (e.g. a text string) to which output/error is appended; a reference to a subroutine which is called, passing the output as a parameter; or any object reference which implements a 'print' method (e.g. IO::Handle, Apache::Request, etc.) which will be called, passing the generated output as a parameter.

So when you send template1 to send_mail you're actually sending a blessed template object (hash). And, your double output is presumably the confirmation screen reading from STDIN, (which your writing to twice, because your not sending process a third var)

On top of that

• prefixing the func with '&' should be thought of as deprecated in non-reference notation and has a side effect if you aren't explicit about arguments.
• I'd use a module for this
• use parallel assignment  my ( $to_address, $from, $subject, $content ) = @_;