Push e-mail

Push e-mail is used to describe e-mail systems that provide an always-on capability, in which new e-mail is actively transferred (pushed) as it arrives by the mail delivery agent (MDA) (commonly called mail server) to the mail user agent (MUA), also called the e-mail client. E-mail clients include smartphones and, less strictly, IMAP personal computer mail applications.

Comparison with polling e-mail

Regardless of whether the receiver uses polling e-mail, outgoing mail is generally pushed from the sender to the final mail delivery agent (and possibly via intermediate mail servers) using Simple Mail Transfer Protocol. However, if the receiver uses a polling email delivery protocol, the final step from the last mail delivery agent to the client is done using a poll. Post Office Protocol (POP3) is an example of a polling email delivery protocol. At login and later at intervals, the mail user agent (client) polls the mail delivery agent (server) to see if there is new mail, and if so downloads it to a mailbox on the user's computer. Extending the "push" to the last delivery step is what distinguishes push e-mail from polling e-mail systems.

The reason that polling is often used for the last stage of mail delivery is that, although the server mail delivery agent would normally be permanently connected to the network, it does not necessarily know how to locate the client mail user agent, which may only be connected occasionally and also change network address quite often. For example, a user with a laptop on a WiFi connection may be assigned different addresses from the network DHCP server periodically and have no persistent network name. When new mail arrives to the mail server, it does not know what address the client is currently assigned.

The Internet Message Access Protocol (IMAP) provides support for polling and notifications. When a client receives a notification from a server, the client may choose to fetch the new data from the server. This makes retrieval of new messages more flexible than a purely-push system, because the client can choose whether to download new message data.

Mobile users

Although push e-mail had existed in wired-based systems for many years, one of the first uses of the system with a portable, "always on" wireless device outside of Asia was the BlackBerry service from Research In Motion. In Japan, "push e-mail" has been standard in cell phones since 2000.^{[citation needed]}

Apple iPhone and iPod Touch

Apple's iPhone and iPod Touch support Yahoo! push e-mail, Hotmail push e-mail (activated through the Dinsdale Panel), Gmail push e-mail (via Google Sync) and Microsoft's Exchange ActiveSync platform, allowing them to synchronize e-mail, calendars and contacts with a Microsoft Exchange Server, Zimbra, NuevaSync or Kerio Connect.^[1] Apple's own MobileMe subscription-service, now known as the iCloud offers support for push email, contacts, and calendars.^[2]

BlacMail

BlacMail, from Fifth C, is a push e-mail solution that supports all major public email systems and targeted at mass-market consumer phones. The solution is unique in that a single client supports both SMS or GPRS as the message bearer, important attributes in the fastest developing mobile markets such as India.^[3]

Google Android

Android's built-in Gmail client uses Google Sync to push e-mail for Gmail accounts set up to sync with the phone.

Android also supports Microsoft Exchange accounts natively through its default mail application. Emails arriving into the Microsoft Exchange inbox are instantly pushed to the device. Calendar events sync both ways between exchange and the device.

Yahoo email is not pushed to an android device. An alternate to lack of native support for yahoo mail is to install the free yahoo mail app which provides instant push email.

Recently also Hotmail has been made push configurable for Android smartphones through the default mail application.^[4]

K-9 Mail, a third-party application for Android, provides IMAP IDLE support.^[5]

Helio Ocean

Helio began adding support to its "ultimate inbox" powered by mFluent LLC for push e-mail to the Helio Ocean in July 2007 with support for Yahoo! Mail, Windows Live Hotmail, and AOL Mail. On April 23, 2008 push support was added for Gmail, along with automatic notifications for POP and IMAP services.^{[6][dead link]}

Microsoft Windows Mobile and Windows Phone

Microsoft began offering real-time e-mail notification with Windows Mobile 2003 (sending SMS messages when new mail arrive), then replaced it with a simulated push experience (long polling) in 2007 with the release of Windows Mobile 5 AKU2^[7] under the name "Direct Push Technology". 'Direct Push' technology is an additional feature added to Microsoft Exchange 2003 with service pack 2 that adds messaging and security features. A phone device running Windows Mobile 5 is enabled to poll Exchange Server every 30 minutes. If new mail arrives in polling interval, it is instantly pulled using a subscriber's existing wireless phone account (this allows device to have changing IP or traverse NAT/Proxy). To achieve push mail with e-mail providers other than Exchange, there is a commercially available plug-in from Emansio that enables push mail with almost any public e-mail provider, or any e-mail server that supports IMAP-IDLE.

Nokia Symbian Series 60

Some Nokia Symbian S60 models support basic IMAP IDLE functionality with its built-in client. But on newer E72, E52 etc. phones this functionality is broken, because connection to the mail server is closed (probably even outside the mailing application) and never restored.[1]

Nokia Mail for Exchange

The Nokia Eseries smartphones and select models of Nseries smartphones and newer s60 and Symbian^3 handsets running symbian os 9.x or Symbian^3 support the Mail for Exchange software, which is compatible with Microsoft Exchange Server Active Sync and Direct Push, allowing the Nokia smartphones to receive push email as well as sync contact lists, calendars, and tasks with Exchange servers. Global Address Lookup is also supported, starting with version 2 of the Mail for Exchange software.^[8]

Nokia Messaging

Nokia Messaging Email is a push e-mail service and client application, that supports most of the popular e-mail providers like Windows Live Hotmail, Yahoo! Mail, Gmail and many more. Nokia Messaging servers aggregate messages from up to ten accounts on and pushes them to compliant devices (Nokia S60 and some S40, plus Maemo-based devices like the N900).^[9][10]

Palm OS

Palm Smartphone devices have had IMAP IDLE^[11] available through the use of 3rd Party software ChatterEmail as early as 2004. There is no additional server software required.

Palm webOS

The Palm Pre webOS has push email for Gmail, IMAP, and Exchange accounts.

Research In Motion BlackBerry

RIM's BlackBerry offers Push email access for Yahoo, Gmail and Hotmail accounts. It uses wireless mail user agent devices and a BlackBerry Enterprise Server (BES) attached to a traditional e-mail system. The BES monitors the e-mail server, and when it sees new e-mail for a BlackBerry user, it retrieves (pulls) a copy and then pushes it to the BlackBerry handheld device over the wireless network.

BlackBerry became very popular, in part because it offers remote users "instant" e-mail; new e-mails appear on the device as soon as they arrive, without the need for any user intervention. The handheld becomes a mobile, dynamically updating, copy of the user's mailbox. As a result of the success of BlackBerry, other manufacturers have developed push e-mail systems for other handheld devices, such as Symbian- and Windows Mobile-based mobile phones.

SEVEN Networks

SEVEN Networks supports consumer and enterprise email including Gmail, Yahoo Mail, Windows Live (Hotmail, Live.com, MSN), AOL, Microsoft Exchange, IBM Lotus and other local web-based email providers on Android, bada, Brew, J2ME, Symbian and Windows Mobile devices.

Sony Ericsson

Sony Ericsson Smartphones (M600, P990, W950, P1, W960, W995, G900, G700) as well as some Cybershot phones (K790, K800, K810, K850, C510, C905,J105i) feature push e-mail using IMAP IDLE or with the built-in ActiveSync client (developed by Dataviz). Most other Sony Ericsson phones support IMAP IDLE push e-mail quite well (only the inbox however).

Other mobile solutions

Other push e-mail solutions available in the market today are Emoze, NotifyLink, Mobiquus, SEVEN Networks, Atmail, Good Technology as well as Synchronica.

NotifyLink supports the following backends: Axigen, Alt-N Technologies, CommuniGate Pro, Kerio Connect, Meeting Maker, Microsoft Exchange 2000/03/07, Mirapoint, Novell GroupWise, Oracle, Scalix, Sun Java Communications Suite, and Zimbra, plus other solutions for e-mail only. The supported mobile devices/operating systems include Windows Mobile, BlackBerry, Symbian OS and Palm OS.

Mobiquus is a push email client based on J2ME technology. Also, it can visualize most attachments (images, videos, Office files...) without the need of having other applications installed on the phone.

Good Technology's Good Mobile Messaging (formerly known as GoodLink) supports Microsoft Exchange 2000, 2003 and 2007 as well as Lotus Notes.

Visto supports Exchange 5.5/2000/2003, Domino all versions and works with any ISP e-mail. Visto acquired Good in May 2009 and changed its name to Good.

Synchronica provides a client-less, carrier-grade push Email and synchronization solution based entirely on open industry standards. Their core product, Mobile Gateway, supports push mail standards like IMAP, IDLE and OMA EMN as well as PIM synchronization using OMA DS (SyncML). Towards backends, it supports POP, IMAP, Microsoft Exchange and Sun Communications Suite.

Peek provides mobile push email for consumers. They have their own device, very much like the BlackBerry. Peek supports POP and IMAP, with compatibility to 'Yahoo! Mail', 'AOL Mail', 'Hotmail', and 'Gmail'. The Peek device is email and texting only and does not provide voice service.

Atmail offer a complete Push mail, calendar and contact server for Linux. From licensing ActiveSync from Microsoft, Atmail offer Push mail capabilities to exiting IMAP servers such as Dovecot, Courier, UW-IMAP and more.

Another company to offer a push e-mail solution is Critical Path, Inc. under the brand name Memova Mobile, the only requirement of this is that the handset have GPRS and MMS capability.

Most of these non-proprietary solutions are network independent, meaning that as long as a device is data enabled and has an e-mail client, it will have the ability to send/receive e-mails in any country and via any telco that has data service on its network. It also means that so long as the device itself is not SIM locked (in the case of GSM systems), the constraints of BlackBerry such as network locking, vendor locking (BlackBerry devices and BlackBerry Connect devices) and data-roaming charges (for non-home access) are not an issue. For a GSM system, pop in a local SIM card in any country the user is in, have the correct APN settings and get your mail at LOCAL rates.

Emoze

Emoze is a mobile devices push service application in which you may choose your phone, your operator and your network. This mobile solution is based on a patented synchronization process (Publication number US 2007/0208803 A1 ^[12]) that enables synchronized, push email on a wide variety of mobile devices via any mobile network operator. This enables mobile users to send and receive data from multiple email accounts while keeping their personal information (contacts and calendar) synchronized. It enables the user to manage multiple accounts (ISP^[13], GMAIL, YAHOO end others). Emoze supports almost every data enabled mobile phone and is not limited to smartphones. Using this solution mobile users may view HTML formatted emails and may download and view attachments, pictures, music, documents depending on their device capabilities and/or have access to contact lists from social networks as Facebook, MySpace, Bebo, Orkut and others.

The Emoze technology, called Smart Routing was designed to provide a seamless and secure messaging for the end users. Data is constantly synchronized, in real-time, only when the mobile device is on and connected to the Internet. The user's privacy is protected and secured by enabling messages to be pushed from the originating mail server to the mobile device without storing it on an intermediate server. Private data is not being stored on a third party server thus avoiding data loss and corruption. Whenever there is a new event (email, contact or calendar) on the mail server or mobile device, the synchronization is processed immediately.

Emoze was the first push email solution for mobile devices without a server side software^[14].

Simulation using traditional e-mail

Traditional mobile mail clients may poll for new mail at frequent intervals, with or without downloading the mail to the client, thus providing a similar user experience as push e-mail.

IMAP in fact allows many notifications to be sent at any time, but not message data. The IDLE command is often used to signal the ability of a client to process notifications sent outside of a command running, which effectively provides a user experience identical to push.

Protocols

In contrast to traditional e-mail, most of the protocols used in popular current systems are proprietary; for example, BlackBerry uses its own private protocols developed by RIM. Both the Push-IMAP standard and parts of the SyncML standards are attempting to develop more open solutions.

IETF Lemonade is a set of extensions to IMAP and SMTP to make them more suited to the demands of mobile e-mail. Among the extensions are rapid IMAP resynchronization and a new NOTIFY command in IMAP.

References

1. ^ Corporate E-mail Coming to iPhone - Look Out BlackBerry! - Switched
2. ^ Apple Introduces MobileMe Internet Service
3. ^ 'BackupBerry' Options for BlackBerry Addicts
4. ^ Craddock, Dick. "Hotmail now supports push email, calendar, and contacts with Exchange ActiveSync". http://windowsteamblog.com/windows_live/b/windowslive/archive/2010/08/30/hotmail-now-supports-push-email-calendar-and-contacts-with-exchange-activesync.aspx. Retrieved 30 Aug 2010. 
5. ^ K-9 Mail Issue 4: Use IMAP IDLE for push email.
6. ^ Gmail (and POP/IMAP!) gets Push support in Ultimate Inbox - heliocity.net
7. ^ Mobile-review.com
8. ^ Nokia - Mail for Exchange
9. ^ Nokia - Nokia Email service
10. ^ Nokia - Nokia Email application
11. ^ Palm.com
12. ^ Levi, Moshe. "Method and System for Email and PIM Synchronization and Updating". http://www.google.com/patents?id=haWgAAAAEBAJ&printsec=frontcover&dq=moshe+levi&hl=en&ei=OEk-TpR3h6H5BtXBqLEC&sa=X&oi=book_result&ct=result&resnum=1&ved=0CCgQ6AEwAA. Retrieved 8 Aug 2011. 
13. ^ Reuters.com (February 12, 2008). "emoze Enables Push Email for Everybody's ISP Account". http://www.reuters.com/article/2008/02/12/idUS108811+12-Feb-2008+PRN20080212. Retrieved 8 Aug 2011. 
14. ^ news.thomasnet.com. "emoze Launches First-Ever Free Global Service for Push Email without Server Side Software". http://news.thomasnet.com/companystory/emoze-Launches-First-Ever-Free-Global-Service-for-Push-Email-without-Server-Side-Software-514700. Retrieved 8 Aug 2011.