Thanks for the lead.

It means sendmail is finding it difficult to deliver your mail. Try printing out a "good" e-mail to a text file (or use the dead.letter you found, though you might have to edit it a bit), and pipe it through sendmail yourself:

$ sendmail -t <message
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See if sendmail says anything to you.

sub SendMail {
    if (-e $FORM{'template'}) { }
    else { &Error('Template File Not Found - Error at sendmail subscri
+pt'); }
    
    open (FILE, $FORM{'template'});
    @File = <FILE>; close (FILE);
    open (MAIL, "|$mailprog -t") || &Error('Unable to Open Sendmail');
    print MAIL "To: $FORM{'mailto'}\n";
    print MAIL "From: $FORM{'req-EMail'} ($FORM{'req-FName'} $FORM{'re
+q-LName'})\n";
    print MAIL "Subject: $FORM{'subject'}\n";
    print MAIL "Bcc: \n\n";
    print MAIL "This information request form is from the Rainforest &
+ Reef Resorts of Belize website.\n";
    print MAIL "*************************************************\n";
    print MAIL "This form was submitted at $time by $FORM{'req-FName'}
+ $FORM{'req-LName'} ($FORM{'req-EMail'}).\n";
    print MAIL "For your records, this is Form Request Number \= $Orde
+r from this website.\n";
    print MAIL "*************************************************\n\n"
+;

    foreach $File (@File) {
        $File =~ s/\n//;
        foreach $Field (@InputFields) {
            $ReplaceVar = $FORM{$Field}; 
            $SearchVar = '\[' . $Field . '\]';
            $File =~ s/$SearchVar/$ReplaceVar/g; 
        }        
    print MAIL "$File\n"; }
    close (MAIL);
}
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After performing this subroutine, it then:

sub Redirect {
    if ($FORM{'success'}) { 
        print "Location: $FORM{'success'}\n\n"; }
}
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Any ideas?

Hmmm, well Some hints (no big help though):

  sub SendMail {
#  add debugging
      my $debug = 6;
      if (-e $FORM{'template'}) { }
      else { &Error('Template File Not Found - Error at sendmail subsc
+ript'); }
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Normally (note adding the missing file name to error msg):

   
if ( ! -e $FORM{'template'}) {
     &Error('Template File $FORM{template} Not Found - Error at sendma
+il subscript'); 
}

      open (FILE, $FORM{'template'});<br>
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always:

   
      open (FILE, $FORM{'template'}) or die "can't open FILE $FORM{tem
+plate}: $!";<br>
   
      @File = <FILE>; close (FILE);
      open (MAIL, "|$mailprog -t") || &Error('Unable to Open Sendmail'
+);
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Try:

      open (MAIL, "|$mailprog -t") || &Error("Unable to Open $mailprog
+: $!");
print "<p>trying: $mailprog -t<br>
To: $FORM{mailto}<br>
From: $FORM{req-EMAIL} ($FORM{req-FName} $FORM{req-LName})<br>
Subject: $FORM{subject}<br>\n"
    if $debug > 5;
      print MAIL "To: $FORM{'mailto'}\n";
      print MAIL "From: $FORM{'req-EMail'} ($FORM{'req-FName'} $FORM{'
+re
  +q-LName'})\n";
      print MAIL "Subject: $FORM{'subject'}\n";
      print MAIL "Bcc: \n\n";
      print MAIL "This information request form is from the Rainforest
+ &
  + Reef Resorts of Belize website.\n";
      print MAIL "*************************************************\n"
+;
  +
      print MAIL "This form was submitted at $time by $FORM{'req-FName
+'}
  + $FORM{'req-LName'} ($FORM{'req-EMail'}).\n";
      print MAIL "For your records, this is Form Request Number \= $Or
+de
  +r from this website.\n";
      print MAIL "*************************************************\n\
+n"
  +;

      foreach $File (@File) {
          $File =~ s/\n//;
          foreach $Field (@InputFields) {
              $ReplaceVar = $FORM{$Field}; 
              $SearchVar = '\[' . $Field . '\]';
              $File =~ s/$SearchVar/$ReplaceVar/g;
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This is odd, does each file (file name) possibly have every/any input field w/i it? Anyway, this is/may be 'cooler'

  $File =~ s/\[$Field]/$FORM{$Field}/g;  # do you need an 'e' too?
          }        
      print MAIL "$File\n"; }
      close (MAIL);
  }
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Only thing I can see is that, as you don't (here) verify the sender's address or the To: address, it may have junk in there that sendmail doesn't like. Do you need pointy brackets around the actual To|From address parts?

a