Repair Email issue at IdealHoroscope.com

The site is hosted on my own server, which runs Ubuntu with Vesta Control Panel. Visitors can submit their details at the above site and receive a free personalised horoscope. They also get a Daily Prediction email every day, that is generated by an API connection with VedicRishiAstro.com. The domain is not able to receive emails from outside. Fix this error and restore function of email. Before you apply, have you signed up for the free astrology chart in order to personally test the deliverability of the email? NO phone calls or emails; Freelancer applications only. When could you have this finished by?