One SMTP service provider prevented emails from going out (v1.17 on PHP8.0 & PHP8.1) and Gmail blocked or "soft-bounced" the email upon receipt due to the same reason - the emails sent from OSTicket via SMTP have 2x Date Headers:

I managed to temporarily fix this by editing the file located at include\laminas-mail\src\Message.php
commenting out lines 102 and 103:

Our host is closing PHP7.4 support in a couple of hours, so this allows us to continue using OSTicket - any ideas or feedback on how this could perhaps be better addressed from our side? Is this something that should be fixed by
Laminas?