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Push mail


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This article is for an insight of the "Push Mail" technology employed by almost all service providers. It a technology by which you receive your emails without the need to Log In into your email. Read the complete article for more details.

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Push mail

  1. 1. PUSH MAIL WHAT IS PUSH EMAIL?Push email is a method of pushing content (email in this case) over the internet toyour targeted audience. When most people think of “push” email, they think of havingemail arrive (whether on their smart phone or their PC) as soon as it arrives at their mailserver. Either that or they think of RIM’s BlackBerry devices.In practice, email is not received on the smart phone the instant at which it is received onthe mail server generally, there is a few seconds’ delay, but, this tends to be accepted.An example of a “push” implementation:  Alan is out of the office, but wants to keep up with his email as and when they arrive- he sets up “push” email on his smartphone, and heads off to his meeting.  Ben sends an email to Alan’s email address.  The email travels across the Internet (remember- email is inherently insecure), until it finds Alan’s mail server.  When it reaches Alan’s mail server, it is immediately pushed to Alan’s smartphone, for Alan to read.Technically Push Mail can be defined as a e-mail systems that provide an always-oncapability, in which new e-mail is actively transferred (pushed) as it arrives by the maildelivery 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, IMAPpersonal computer mail applications.Push email utilizes a mail delivery system with real-time capability to “push” emailthrough to the client as soon as it arrives, rather than requiring the client to poll andcollect or pull mail manually. With a push email smartphone, for example, the client’smailbox is constantly updated with arriving email without user intervention. Smartphonesannounce new mail arrival with an alert.Hardeep Singh Bhurji Page 1 of 10
  2. 2. PUSH MAILPush email differs from conventional email systems that are “pull” oriented. Usually,when email is sent, it arrives at the recipient’s Internet Service Provider’s (ISP’s) mailserver, where it is held for collection. It might instead arrive at a website server, if theemail is Web-based. Either way, email remains on the mail server until the recipient usesan email program to poll the mail server. If new mail is present, the email client “pulls”the mail to the client’s computer. The difference between this scheme and push email isthat, with push email, the mail is pushed through to the client without waiting for polling.Regardless of whether the receiver uses polling e-mail, outgoing mail is generally pushedfrom the sender to the final mail delivery agent (and possibly via intermediate mailservers) using Simple Mail Transfer Protocol. However, if the receiver uses a pollingemail delivery protocol, the final step from the last mail delivery agent to the client isdone using a poll. Post Office Protocol (POP3) is an example of a polling email deliveryprotocol. At login and later at intervals, the mail user agent (client) polls the mail deliveryagent (server) to see if there is new mail, and if so downloads it to a mailbox on the userscomputer. Extending the "push" to the last delivery step is what distinguishes push e-mailfrom polling e-mail systems.The reason that polling is often used for the last stage of mail delivery is that, althoughthe 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 beconnected occasionally and also change network address quite often. For example, a userwith a laptop on a WiFi connection may be assigned different addresses from thenetwork DHCP server periodically and have no persistent network name. When newmail arrives to the mail server, it does not know what address the client is currentlyassigned.The Internet Message Access Protocol (IMAP) provides support for polling andnotifications. When a client receives a notification from a server, the client may choose tofetch the new data from the server. This makes retrieval of new messages more flexiblethan a purely-push system, because the client can choose whether to download newmessage data.Hardeep Singh Bhurji Page 2 of 10
  3. 3. PUSH MAILPush email can be somewhat simulated using an email client set to frequently poll fornew mail. However, this requires the email client to be open and running and is lessefficient. Polling involves “handshaking” between the client software and the mailserver. If the server is busy, the delay in completing the handshake can lengthen, causingthe client to time out. Therefore, polling should not be set so frequently as to causepremature time out errors. To prevent this, one must increase the delay between pollingtimes.In many cases, a minute or two delay between “pull email” and push email schemes maynot matter, but in some cases, a minute can make all the difference. Push email can beespecially crucial to field reporters, stock market businessmen and otherprofessionals for whom time is of the essence. A one-minute delay can make all thedifference in breaking a story, losing money, or making a crucial sale.Although push e-mail had existed in wired-based systems for many years, one of the firstuses of the system with a portable, "always on" wireless device outside of Asia was theBlackBerry service from Research In Motion. In Japan, "push e-mail" has beenstandard in cell phones since 2000.BlackBerry was the first personal digital assistant (PDA) to offer push email and gainednear-instant success as a result. Today, many devices have incorporated push email, andits popularity continues to grow. Some of the products that have incorporated push emailinclude Chatteremail for Treo, Nokia Intellisync Wireless Email, Roadsync, andSony Ericsson phones.Hardeep Singh Bhurji Page 3 of 10
  4. 4. PUSH MAIL PROTOCAL USED IN PUSH MAIL TECHNOLOGYIn contrast to traditional e-mail, most of the protocols used in popular current systems areproprietary; for example, BlackBerry uses its own private protocols developed by RIM.Both the Push-IMAP standard and parts of the SyncML standards are attempting todevelop more open solutions.IETF Lemonade is a set of extensions to IMAP and SMTP to make them more suited tothe demands of mobile e-mail. Among the extensions are rapid IMAP resynchronizationand a new NOTIFY command in IMAP. SOME POPULAR PUSH MAIL SETUPSThe Bottom fact is that there exist different Push Mail solutions and different Push Mailsolutions works in different ways. Lets us go in some more details.Microsoft’s Direct Push:For example, with Microsoft’s Direct Push system, the smartphone sends an HTTPrequest to the Exchange server, asking to be notified when something (email, calendarappointment etc) changes on the server. This request lasts for the shorter of (a) a timeoutperiod and (b) a change on the server. If there is a change, the Exchange server respondsto the smartphone with details of the folders in which the changes have occurred. Uponreceiving this response, the smartphone sends a synchronization request in respect ofeach of the folders notified by the server, and the server delivers the details of thechanges – depending on signal strength / connection speed, this takes between 5 and 10seconds.Hardeep Singh Bhurji Page 4 of 10
  5. 5. PUSH MAILIf there is no change within the timeout period, the Exchange server sends an emptyresponse to the smartphone. In either case, when the smartphone receives the Exchangeresponse, it reissues the HTTP request – essentially, this is a looping process, and theissue / receive loop is often referred to as the “heartbeat”. Each heartbeat is 309 bytes,and, by default, a heartbeat is issued every 15 minutes. Thus, in addition to the size ofany of the actual changes, the figure usually linked to the heartbeat is approximately1MB / month (309B * 4 (number of 15 minute periods in an hour) * 24 (number of hoursin the day) * 31 (maximum number of days in a month) = 919584B = approximately898KB.The IMAP IDLE Push:The IMAP IDLE system works in a similar manner. A “traditional” IMAP system worksby notifying the smartphone of any changes in the folders on the server when the user isactively monitoring the server; however, this only works when the mail client on thesmartphone is active, and thus notifications stop when a user stops using the mailapplication or puts the smartphone away. IMAP IDLE issues a “NOOP” (“NoOperation”) command to the IMAP server at a regular interval, usually every 15 minutes.By sending this command, the connection is kept active, and thus the user is notified ofany changes. This is different to Direct Push system above, in that there is no issue /receipt loop, but the overall effect and implementation of the IMAP IDLE “NOOP” issueis similar.RIM BlackBerry Push:RIM provides two solutions. One for Corporate and other for individuals. Theimplementation is more or less same but the working is different.Hardeep Singh Bhurji Page 5 of 10
  6. 6. PUSH MAILIn case of Corporate Service BlackBerry push technology requires the installation of aserver solution that sits between an organization’s corporate email server and the firewall.Enterprise applications running under Microsoft Exchange, Lotus Domino and NovellGroupWise can be accessed by BlackBerry using the BlackBerry Enterprise Server. Theserver solution integrates with the email server to allow users emails and PIM data to besent through the firewall to a carriers mobile network via the internet. The data is thensent to the specific users device. The server application provides encryption to the data inorder for secure transmission.To receive data RIM uses a Network Operating Centre (NOC). By using a NetworkOperating Center (NOC), the BlackBerry method represents the most battery and dataefficient method for push email. Here the email is forwarded to your BlackBerry by theRIM-operated NOC only when there is email. And even then, only the first chunk ofemail is sent. The data is sent via normal UDP packets that are encrypted at the datalevel. As you can imagine, this will allow it to work the same way via 2G or 3Gnetworks. To find out if there is a mail or not the NOC needs to constantly poll the inbox.For example, a BES server will check every Blackberry-connected mailbox on anExchange server in a round-robin fashion. Once there is a mail the NOC encrypts the dataand sends it to the device immediately where ever it is located. This is achieved becauseRIM registers itself with the Telecom Service Provider. Because of this setup the serverof the Telecom Service Provider forwards the information about the device networkaccess to the RIM NOC. The result is that the NOC now knows exactly where to forwardyour emails to.In case of normal users the setup is same except that there is no different setup to sendmails as above. The setup to receive the mail is same.In the absence of email, nothing at all happens, and your BlackBerry behaves much like anormal mobile phone.Hardeep Singh Bhurji Page 6 of 10
  7. 7. PUSH MAIL DIFFERENT PUSH MAIL PROVIDERSApple iPhone and iPod TouchApples 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) andMicrosofts Exchange ActiveSync platform, allowing them to synchronize e-mail,calendars and contacts with a Microsoft Exchange Server, Zimbra, NuevaSync or KerioConnect. Apples own MobileMe subscription-service for push email, contacts, andcalendars is also supported.Google AndroidAndroids built-in Gmail client supports push e-mail for Gmail accounts set up to syncwith the phone. Android also supports exchange accounts natively through its defaultmail application Recently also Hotmail has been made push configurable for androidsmartphones through the default mail application.Helio OceanHelio 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 LiveHotmail, and AOL Mail. On April 23, 2008 push support was added for Gmail, alongwith automatic notifications for POP and IMAP services.Microsoft Windows Mobile and Windows PhoneMicrosoft began offering real-time e-mail notification with Windows Mobile 2003(sending SMS messages when new mail arrive), then replaced it with a simulated pushexperience (long polling) in 2007 with the release of Windows Mobile 5 AKU2 under thename "Direct Push Technology". Direct Push technology is an additional feature addedHardeep Singh Bhurji Page 7 of 10
  8. 8. PUSH MAILto Microsoft Exchange 2003 with service pack 2 that adds messaging and securityfeatures. A phone device running Windows Mobile 5 is enabled to poll Exchange Serverevery 30 minutes. If new mail arrives in polling interval, it is instantly pulled using asubscribers existing wireless phone account (this allows device to have changing IP ortraverse 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 withalmost public e-mail provider or any e-mail server that supports IMAP-IDLE.Additionally, a free, open-source, executable has been developed to take advantage of theIMAP-IDLE command. Since 2010 there is new application called Schedhandler, whichcan handle IMAP accounts (+ idle support). It implements a new technology to reducethe power consumption of WM phones, check network connections, and handle anyproblems. If a new email found, then the user can configure what should happen (e.g.polling any pocket outlook mailbox, execute a command, etc.). It is also possible toconfigure a schedule when it should check your emails.Nokia Symbian Series 60Some Nokia Symbian S60 models support basic IMAP IDLE functionality with its built-in client.Nokia Mail for ExchangeThe Nokia Eseries smartphones and select models of Nseries smartphones and newer s60handsets running Symbian os 9.x support the Mail for Exchange software, which iscompatible with Microsoft Exchange Server Active Sync and Direct Push, allowing theNokia smartphones to receive push email as well as sync contact lists, calendars, andtasks with Exchange servers. Global Address Lookup is also supported, starting withversion 2 of the Mail for Exchange software.Nokia MessagingNokia Messaging Email is a push e-mail service and client application, that supports mostof the popular e-mail providers like Windows Live Hotmail, Yahoo! Mail, Gmail andHardeep Singh Bhurji Page 8 of 10
  9. 9. PUSH MAILmany more. Nokia Messaging servers aggregate messages from up to ten accounts on andpushes them to compliant devices (Nokia S60 and some S40, plus Maemo-based deviceslike the N900) at the time its not a free applicationPalm OSPalm Smartphone devices have had IMAP IDLE available through the use of 3rd Partysoftware ChatterEmail as early as 2004. There is no additional server software required.Palm webOSThe Palm Pre webOS has push email for Gmail, IMAP, and Exchange accounts.Research In Motion BlackBerryRIMs BlackBerry uses wireless Mail User Agent devices and a BlackBerry EnterpriseServer (BES) attached to a traditional e-mail system. The BES monitors the e-mailserver, and when it sees new e-mail for a BlackBerry user, it retrieves (pulls) a copy andthen 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 userintervention. The handheld becomes a mobile, dynamically updating, copy of the usersmailbox. As a result of the success of BlackBerry, other manufacturers have developedpush e-mail systems for other handheld devices, such as Symbian- and Windows Mobile-based mobile phones.SEVEN NetworksSEVEN Networks supports consumer and enterprise email including Gmail, Yahoo Mail,Windows Live (Hotmail,, MSN), AOL, Microsoft Exchange, IBM Lotus andother local web-based email providers on Android, bada, Brew, J2ME, Symbian andWindows Mobile devices.Hardeep Singh Bhurji Page 9 of 10
  10. 10. PUSH MAILSony EricssonSony Ericsson Smartphones (M600, P990, W950, P1, W960, W995, G900, G700) as wellas 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 theinbox however).Other mobile solutionsOther push e-mail solutions available in the market today are Emoze, NotifyLink,Mobiquus, SEVEN Networks, Atmail, Good Technology as well as Synchronica.Emoze supports Gmail/GApps, Yahoo Mail, Facebook Mail, Hotmail amongst others.Mobiquus is a push email client based on J2ME technology. Also, it can visualize mostattachments (images, videos, Office files...) without the need of having other applicationsinstalled on the phone. CONCLUSIONSo we have seen that “PUSH MAIL” is a revolutionary technology related to onlinecommunication. It is already very popular and people become more and more technologysavvy and life getting more busier PUSH MAIL technology will invade further in oneslife. In future we will use is more to save our valuable time and get updates faster. I alsoexpect that this technology will become much more sophisticated in coming days.Hardeep Singh Bhurji Page 10 of10