You have a common precedence issue. Change the following line.

open FILE, $filename || die $!;
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to

open FILE, $filename or die $!;
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or if you really want to use ||

open(FILE,$filename) || die $!;
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also it wouldn't hurt to be more verbose:

die "Could not open $filename: $!\n";
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UPDATE: The usage of the \g modifier is for multiple matching,substituting,etc. you don't need it if you know what you are searching for only occurs once as is the case:

The original value of $from is "--from me@mydomain.com \"

EXAMPLE:

$str ='abcd';
$str =~s/a//g; # \g unnecessary
##
$str = 'abacad';
$str =~s/a//g; # more appropriate
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It wouldn't hurt to also have a look at perlop

-tengo mas que aprender