This troubleshooting guide will teach you how to solve the syntax error email sending problems.
The problem appears when you try to send a reply via your Helpdesk. And then, unexpectedly, your message is not sent and you get the following error warning on the top of the ticket.
The problem appears to you because there are unexpected, most likely set by mistake, symbols in the email address of some of your contacts.
To fix it, you have to into your Contacts section and find the contact that has the unexpected symbol. And then, please edit this contact and fix the mistake in the email address.