IPhone 5 Emails not coming through instantly?

I have an iPhone 5 with ios7 and my email aren't coming through as I receive them. I have to go on my emails and then refresh it and the mails come through then. I've asked people with iPhones and for them the emails come automatically. Can anyone help? Cheers

Go to settings,
Go to mail, contacts and calendars
Press fetch new data
At the bottom, it will give 4 options.:
Every 15 minutes
Every 30 minutes
Hourly
Manually
*press on manually for your mail to automatically come through without you having to update you mail box.

Hope this helps.

Normal email accounts must be 'polled' to check for new mail on the server.

This normally occurs every ten minutes to hourly, depending on the email client (ie. Your phone) settings.

If you never get any mail other than by manually refreshing it, check the settings for the account & see what the polling interval is.

Go to Settings, Mail Contacts & Calendar, Fetch New Data:

For the email account it should say 'Fetch' and one of the time intervals below should be ticked - manual in either fetch or as an interval prevents automated polling.