I need help with yahoo email?

ok, so obviously my account is with yahoo.com. my emailing time is way off like if someone sent me an email at 5:00PM, the time on the email it would say 10:00AM. I've tried what people said about changing the time zone but that still didn't work. my computer time is fine but the email time is way off. CAN SOMEONE PLEASE HELP ME, POR FAVOR???????