When emails are sent from osTicket 1.17, the "Date" line appears twice in the body of the email. Some mail providers may ignore it, but some may not. For example, IONOS returns emails with the error "554-Reject due to policy restrictions. 554 For explanation visit https://www.ionos.com/help/index.php?id=2425&ip=80.68.155.194&c=hd" . I fixed it by commenting out line 350 of "include/class.mailer.php".
lpascual
You should always stay on top of upgrades. This has already been addressed. You can upgrade to v1.17.2, update all plugins you have installed, and you should be good.
Cheers.
