In the last few years, certainly spanning iOS 8 and iOS 9, you may have experienced a bug with the Mail app on iPhone not updating in the background. Here’s one solution that may fix it.
The way Apple Mail on iOS should work is simple – unlike other iPhone apps there is no ‘background app refresh’ option, you choose between ‘Push’, ‘Fetch’ and ‘Manual’. ‘Push’ is the most common with email accounts these days, forming a constant connection with your email provider to allow it to send emails straight to your phone.
The exception, however, on iOS is Gmail, for which Google has discontinued the feature outside of the official Gmail app. Gmail however should still use ‘Fetch’, a setting which means your iPhone contacts the email server at a specified time (either every 15 minutes, 30 minutes, or hourly) and retrieves any outstanding emails. These settings are available for any email service which supports them, including Apple’s own iCloud, Hotmail, Yahoo, BT, Exchange and others.
It can be the case though that while you have your email account settings setup correctly (ie. not on ‘Manual’), Apple Mail simply doesn’t update. You may find that email notifications don’t appear and only when you launch the Mail app and manually swipe down to refresh in the inbox will the emails appear.
Luckily there’s a simple fix that may work: Check your data roaming settings are turned ON. On iOS 9 this is found under Settings > Mobile Data (also called ‘Cellular’ in certain Countries) > Data Roaming
If you find this setting is off – probably from when you went abroad and forgot to turn it back on – it may well be the cause of your email not refreshing. You may also need to restart your phone for the setting to fully update.