iPhone E-mail

Unlike many other smartphones, your iPhone can send, receive, and browse e-mail without getting weighed down with compromise. The iPhone doesn�t settle for cramped, odd presentations. Your e-mail looks the way it should�the way it would if you were reading it on your home computer. That�s because the iPhone provides an HTMLcompatible rich-text client. Mail looks better because the client is better. It�s made to work right.

iPhone mail works with most industry-standard e-mail systems. With it, you can send and receive photos; view Excel spreadsheets, PDF files, and Word documents; manage your accounts; and more.


Compatibility
iPhone Mail is surprisingly compatible. It works with virtually all major e-mail providers, including Gmail, AOL, Yahoo!, and Comcast. For businesses, iPhone plays relatively well with Microsoft Exchange. This high level of provider support is because of the iPhone�s support of industry-standard protocols. The iPhone understands the most popular email standards, namely, POP, IMAP, SMTP, and Exchange. If you�re not already familiar with these standards, here�s a brief overview.


POP
POP (aka POP3) stands for Post Office Protocol. It�s probably the most common e-mail retrieval protocol in use today. It allows mail clients to connect to a server such as Gmail or AOL, retrieve messages, and disconnect afterward. This usually happens on a set schedule, such as every ten minutes or every hour; you do not receive mail until your client connects to the server and requests that new mail. POP works by checking in with a server, downloading your e-mail, and optionally leaving the original copies of your e-mail on the server. This leave-on-server option works well with the iPhone, because when you�re on the go, you probably want to check your mail on the iPhone and retrieve it again later when you get back to the office or return home. POP also has its downsides. Unlike the newer and improved IMAP protocol, POP downloads entire messages all at once, so it�s a bit of a space hog on portable devices. The 3 in POP3 indicates the third version of the protocol standard; POP1 and POP2 are obsolete.


SMTP
Mail clients use one protocol for receiving mail and another for sending mail. Your iPhone uses Simple Mail Transfer Protocol (SMTP) to send outgoing messages. SMTP contacts a mail server and transmits messages you�ve written along with any attachments including text, photos, and so forth. A common kind of SMTP, called SMTP-AUTH (AUTH stands for authorization), allows you to send secure, authorized mail. You provide your account name and a password. Your mail client authenticates itself to the server, and your e-mail is sent on its way.

The iPhone makes sending authenticated e-mail easy. Enter your account name and password into the Mail settings pane. Once you�ve done this, just use outgoing mail to send a note, share a web page�s URL, or pass along a photo that you�ve just snapped with the iPhone�s built-in camera. The iPhone takes care of all the protocol issues. You decide what to send and to whom to send it.


IMAP
IMAP stands for Internet Message Access Protocol. Like POP3, it allows you to receive e-mail on the iPhone. It�s a newer and more flexible protocol. As the name suggests, IMAP was built around the Internet. It introduces advanced ways to connect to the mail server and use the limited bandwidth of mobile connections in the most efficient way. The key to understanding IMAP is to recognize that messages are meant to live on the server rather than go through a retrieve-and-delete cycle. You manage your mail on the IMAP server. You read your mail on a client, like the iPhone.

When you download mail with POP, you download entire messages. When you download mail with IMAP, you download headers instead, at least initially. Headers are the bit that tells you who the mail is from and what it�s about. You don�t download the main body of the message until you explicitly request it from the server. Since the header occupies only a fraction of the space of the message, you can download IMAP data a lot faster than you download POP. The rest of the message stays on the server until you�re ready to read it.

The same thing goes for attachments. Say that someone sends you a 10MB video. It doesn�t get downloaded to your iPhone. It stays on the server until you�re ready to watch it on your home computer. If you�d downloaded the message with POP, the entire video would have transferred with the message. With IMAP, you can read the message that came along with the video without having to download the video file itself until you�re ready to watch it. The video attachment waits for you on the mail server.

IMAP also offers a feature that�s called push e-mail. Geeks will tell you that technically speaking IMAP is not exactly the same thing as push e-mail. True push e-mail reaches out and tells your e-mail client whenever new mail arrives in the system. Instead, your iPhone IMAP client connects to and gently tickles the server until new mail arrives. This kind of always-on connection allows the iPhone to receive mail almost as soon as it arrives on the server. In practice, there�s better intention there with push-style mail than actual results. Yahoo! and Gmail offer free IMAP accounts for iPhone users. To sign up for an account, point your browser to http://mail.yahoo.com or http://gmail.com.


Microsoft Exchange
Microsoft Exchange provides e-mail along with other enterprise-level services intended to support Outlook on the Web, personal computers, and mobile devices. Past versions of the iPhone did not support Exchange without, well, jumping through hoops. Exchange Server administrators had to open all sorts of security holes to get it to work, and they usually weren�t too happy about doing that. Fortunately, iOS 4 provides much better compatibility with Microsoft Exchange, to the point that you can now configure multiple Exchange ActiveSync accounts on your iPhone for business use.

Exchange is more than just e-mail, though�it�s also about sharing calendars and contacts. Since iOS 4, iPhones can receive push e-mail from an Exchange Server, access a company-wide global address list, accept or create calendar invitations, and even search e-mails that are stored on the server.

If you�re using your iPhone in a corporate setting that uses Microsoft Exchange Server, it�s best to work with your IT department to ensure that your device is connected to the server in the most secure way possible. If they�re not familiar with how the iPhone works with Exchange, Apple has provided a white paper on Exchange deployment that is free to download: http://images.apple.com/iphone/business/docs/iPhone_EAS.pdf.

Source of Information :  Taking Your iPhone 4 to the Max