The script has misleading names ($infile is the name of an output file), but I think the likely problem stems from a change in the format of the exclusion file:

open(ROFILE, "<", $mExcludingFile) or die("Can't open $mExcludingFile 
+exception file!");
while(<ROFILE>) {
  push(@mArray, $_);
}
...
[download]

Here, $_ contains the newline from each line in the file. If the file is formatted with Windows-style newlines (\r\n), it will contain \r\n at the end of each line. These lines are collected in the @mArray array (which would likely have better been named @exclusionList or something).

...
      my $mLineNow = "$email $name\n";
...
      foreach $mArrayNow (@mArray) {
        if ($mLineNow eq $mArrayNow) {
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Here, the $mLineNow is built up and a Unix-style newline is added. If the exclusion file was formatted with Windows newlines, these lines will never be identical.

My approach would be to first check if the difference in whitespace is the reason:

xxd excludes/everyone.txt

Check for 0d 0a sequences. If these show up, the file has Windows-style newlines.

I would then modify the code to strip all whitespace from the lines:

open(ROFILE, "<", $mExcludingFile) or die("Can't open $mExcludingFile 
+exception file!");
while(<ROFILE>) {
  s/\s+$//;
  push(@mArray, $_);
}
[download]

...

      my $mLineNow = "$email $name"; # no newline needed here
[download]