My New iPhone

Defining How Often Messages Are Retrieved

You can access email in two ways: Push and Fetch. The Push option works only for certain email accounts, such as MobileMe or Gmail, where the service tries to send new messages to your iPhone as soon as it receives them without your having to do anything. When messages are pushed to your phone, you should receive and be able to read messages within seconds after they're sent to you (theoretically).

The Fetch option works the way most email works, by periodically checking your email account for new messages. Because Fetch checks only periodically, such as every 15 minutes, the time delay between receiving a new message and it actually appearing on your iPhone can vary from a few seconds to several minutes, ...