Failed to open mailbox: Login aborted

[ZaNaToS]

There is a cron installed in Plesk (by default)
that runs this command: /usr/local/psa/admin/bin/php /usr/local/psa/admin/bin/ttsmailparse.php

and In the emails (the reports of cron) all the cron commands with /usr/local/psa/admin/bin/php /usr/local/psa/admin/bin/ttsmailparse.php

have this output : Failed to open mailbox: Login aborted

What is that? is it important?