Autoresponder perl script error

Hi all. The autoresponders of two different accounts and two different domains are not working as they should. Sometimes they do, but 5 out of 6 times, the sender receives a Mailer-Daemon message instead of the autoresponder configured one. Here is an example, including .pm file and line of error at the bottom. From: Mail Delivery System [mailto:Mailer-Daemon@xxxxxx.com] Sent: lunes, 15 de octubre de 2018 13:49 For: sender@yyyyyyy.com Subject: Mail delivery failed: returning message to sender This message was created automatically by mail delivery software. A message that you sent could not be delivered to one or more of its recipients. This is a permanent error. The following address(es) failed: pipe to |/usr/local/cpanel/bin/autorespond autoresponderaccount@accountdomain.com /home/account/.autorespond generated by autoresponderaccount@accountdomain.com The following text was generated during the delivery attempt: ------ pipe to |/usr/local/cpanel/bin/autorespond autoresponderaccount@accountdomain.com /home/account/.autorespond generated by autoresponderaccount@accountdomain.com ------ Argument contains empty host portion of address at /usr/local/cpanel/Cpanel/Email/Object.pm line 168.
Any hint of why is this happening or how to solve it and make autoresponders work correctly would be appreciated. Thank you very much in advanced. Regards.