The Mail App
Even if you're dead-set on using the Gmail app to check your e-mail, there's plenty of reason to also establish your addresses within Apple's Mail app. Generally discourage duplicity with things like this, but as earlier, there are certain benefits to having an e-mail account registered with an app that's so finely woven into the core of iOS. Universal Searches won't pull up findings within your e-mail accounts unless they're established in Apple's own Mail app, and push notifications cannot be sent down through Safari if you're trying to use an e-mail system's web app.
Beyond all that, though, Mail is a fantastic app on its own, but there are an abundance of settings and options to tweak-things that most folks don't ever take the time to investigate. Good thing you aren't lumped into that crowd. Apple makes it stunningly easy to get an e-mail account registered in Mail... provided you're using a Gmail, Yahoo!, Microsoft Exchange, iCloud, Aol, or Hotmail account.
Here's a stunner: Mail setup leads you to all sorts of other non-mail related things. Apple has intelligently realized that you may not want to suck down associated contacts, notes, and calendars for every single e-mail account you load into Mail. To that end, each new account you create gives you the option to toggle the aforementioned extras off or on. If you're looking to add your work e-mail address to Mail just for the sake of having it there in case of an emergency, but you've no desire whatsoever to see any weekly conference calls on your personal calendar, just venture to Settings → Mail, Contacts, Calendars → and select each account individually.
You've probably heard a thing or two about "push" and "pull" systems related to e-mail. The iPhone handles both. Push accounts-such as a Gmail account-automatically alert your iPhone that a new message has arrived, even if it's asleep or idling. It requires no action whatsoever on your end. Naturally, this "always alert" state has a slightly negative impact on battery life (think of it as your iPhone sleeping with one eye cracked open), but more detrimental is the data required. If you're using cellular data, or you're counting kilobytes with more intensity than calories, you may want to disable push altogether.
Note
Added my Engadget work e-mail into the Mail app for one reason, and one reason alone: sharing. Any time a tweet, a YouTube video, or any other piece of media that can be shared via e-mail, Apple forces me to use its Mail app to do the sharing. Until iOS enables you to change the default mail application to a third-party one, you'll have to use an account programmed in Mail to share over e-mail.
To do this, surf over to Settings → Mail, Contacts, Calendars → Fetch New Data. Right up top is a toggle to disable or enable push wholesale.
"Fetch" is another term for "pull," where you give the iPhone a time interval in which to reach out to your connected accounts and pull in anything new since the last polling time. My suggestion is 15 minutes for those addicted to their digital lives, and hourly for everyone else. Manually is fine, but why force yourself to remember what to refresh when the iPhone will do it for you? Push forces updates to your phone as soon as they happen; pull (or fetch) retrieves information on a schedule that you dictate. iCloud information is set to Push, but other third-party accounts give you additional control.
Another tip is to dig one level deeper. If, while in that same window, you tap Advanced, you'll be able to tell each and every mail/calendar account how you want it to push or pull. Perhaps pushing your personal account while only pulling your work account hourly is an ideal situation, as it saves precious battery life and data where you can most afford to.
Mail Settings
In the effort of saving you time, recommend the following settings under the Mail options in Mail, Contacts, Calendars.
- Show → 500 recent messages: It doesn't demand that much extra space, and it's awesome to have a huge history when sifting for something offline.
- Preview → 5 lines: The more glanceable information you can get your hands on, the less time you waste diving deeper into something that's not important.
- Minimum Font Size → Medium: Unless your eyes are troubling you. The Giant setting is highly useful for some, and highly hilarious for everyone else.
- Show To/Cc Label → On: In most cases, the more information you have to glance at when communicating, the better off you are.
- Ask Before Deleting → Off: You can always resurrect things from the Trash if you need to.
- Load Remote Images → Off: Selecting On is a great way to accidentally buy into a phishing scam.
- Organize By Thread → On: Attempting to read e-mails sans threads could cause your iPhone to burst into tears.
There's another hidden gem here that more advanced users may very well appreciate. While in Settings → Mail, Contacts, Calendar → Add Account..., there's a nondescript Other option beneath all the branded, pre-configured solutions. Mysterious! I'll dig into the specifics of popping an unorthodox e-mail account in here in the section "Password and Multiple Account Management," but for now, to draw attention to a foursome of obscure (to the simpleton, anyway) options below Contacts and Calendars. If you were hoping to connect an LDAP or CardDAV account for pulling in the former, or a CalDAV/Subscribed Calendar for the latter, here's your opportunity. Make sure you bring your server address, username, password, and a crafty description, though.
If you're one of those folks (like me-no shame in confessing it) who have a multitude of shared Google Calendars, getting them to populate in the iPhone's Calendar app is far more difficult than it should be. Although you may assume that simply flipping the Calendar toggle to On in your added Gmail account would be enough, that only adds the sole Google Calendar that directly links to said account. If you've access to shared Gcals from your significant other, colleagues, bosses, sports teams, and so on, they won't just "show up." Defies logic, but it's true.