Another approach is to add another level into the hash:

package FunnyEmail;
use strict;
use warnings;
use Email::Simple;

sub new {
    my $class = shift;
    my $simple = Email::Simple->new(...);
    my $self = {simple => $simple};
    bless $self, $class;
}
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Now, you have to redirect all the methods of Email::Simple into the subhash:

our $AUTOLOAD;
sub AUTOLOAD {
    my $self = shift;
    my $simple = $self->{simple};
    my $method = (split /::/, $AUTOLOAD)[-1];
    if ($simple->can($method)) {
        $simple->$method(@_);
    } else {
        die "Cannot run $method\n";
    }
}
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