Hey Patrick,
I’m sorry to hear that your tickets emails are ending up in Spam folders!
That is not something related to our plugins at all—it is indeed related to your server and to possible spam flags that are coming up related to your domain name and/or its email servers.
I would recommend contacting your web host provider for more assistance with this, and I would also recommend looking into using a premium mail delivery system like MailChimp, Mandrill, Postmark, or SendGrid to improve the mail acceptance rates of your emails. Your web host may have a specific option from these ones that they most recommend; ask them for some insight here and I hope it leads to better “deliverability” of your emails!
Best of luck with your project,
George