Emails Not receiving

Dear Sir

I am very much frustrated on the ongoing email issue . I am not receiving any mails which has been sent thru the forms in my website . www.hibasgiftindia.com. I am using yahoomail to receive the orders of my customers. ( infohibas@yahoo.com) .. which is affected very badly .
i am using another mail also for the agents to place their orders (hibasorders@gmail.com) . which is not affected much. but getting late to receive . most of the orders are coming from customers and through yahoo mail only . so this error affected my business a lot .. kindly look in to this matter and fix it ASAP

Regards

Shaji