My iPad is not receiving my emails just started two days ago

What mail provider do you have?

Have you tried to go into the settings, mail, contacts and calendars, delete then re-add your mail account info?

Can I guess your email provider is Yahoo? If so, it is a Yahoo issue, and you will need to deal with them. However, it seems that many users have reported that no matter what they seem to do, it isn't helping, but waiting it out for a period of time is finally allowing Yahoo to function.