lately I have noticed that the times on the emails I receive in my yahoo email account are off by a few hours, I am talking about emails that were sent from the same time zone as me, and emails that I know at what time they were sent, is there any way to fix this?

Get GMail.

Same thing happens to my gmail. Off by a few hours. When I use my friend's comp (also a mac) it seems to be fine.

I do [also] have a [number of] gmail account[s] besides my yahoo account.