Sometimes, it takes a bit for an email to come through on your iPhone via the Mail app. That might be due to the way your iPhone checks mail servers. Here’s a quick way to find out what type of email access your iPhone is doing, and then what kind of fix might be in order.
First up, find out whether your email provider uses the Push method or the Fetch method. Open your Settings app with a tap and then tap into Mail, Contacts, Calendars. Tap on the Fetch New Data section, and then the Advanced option. You’ll see your list of email accounts set up for Mail app on your iOS device. If your provider uses Fetch, like Gmail typically does, you’re in luck.
Back out one settings screen, and tap Every 15 Minutes for your Fetch schedule. This will force your iPhone to go and check email every 15 minutes, instead of the Hourly that it sets up by default. Note that this may cause a hit to your battery life, so be sure to keep an eye on that, as well.
Now your iPhone will check for email more often, getting you a faster turnaround for the email that comes in between Fetches. If your email provider uses Push, you won’t be able to use this method to speed it up much, however.
Via: OS X Daily