my original scenario I have Mail::Sender wrapped in a wrapper class (for reasons that are missing in this example script) which is represented here by csMail:

#-------------------------------------
# PACKAGE INFO

package csMail;
$VERSION = .2;

#-------------------------------------
# PRAGMAS
use strict;
use utf8;

#-------------------------------------
# 3RD PARTY MODULES
use Mail::Sender;


#================================================================
sub new
{
   my ($class,%args) = @_;

   $args{smtp} = 'smtp.nycap.rr.com';
   $args{port} = 25;
   $args{from} = 'default_from' if not defined( $args{from} );
   $args{replyto} = $args{from} if not defined( $args{replyto} );

   ref( my $sender = new Mail::Sender {%args} )  or die $Mail::Sender:
+:Error;
   my $self = bless { sender => $sender }, $class;
   return $self;
}

#----------------------------------------------------------------
sub MailMsg
{
   my ($self,%args) = @_;
   return $self->{sender}->MailMsg(%args);
}

#----------------------------------------------------------------
sub MailFile
{
   my ($self,%args) = @_;
   return $self->{sender}->MailFile(%args);
}

#================================================================
sub descError
{
    return $Mail::Sender::Error;
}
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Here is the script that calls it, generating the same error

#-------------------------------------
# PRAGMAS

use strict;
use utf8;

#-------------------------------------
# IN HOUSE MODULES
use csMail;

#===================================================

    ref( my $mailer = csMail->new() ) or die csMail::descError;

    $mailer->MailMsg(
      to => 'stephen@crescentsun.com',
      msg => 'test message body',
      subject => 'test subject'
    )
    or warn $mailer->descError();
[download]