2. CONTENTS
WHAT IS PUSH EMAIL
PROTOCAL USED IN PUSH MAIL TECHNOLOGY
SOME POPULAR PUSH MAIL SETUPS
DIFFERENT PUSH MAIL PROVIDERS
3. WHAT IS A PUSH MAIL ?
Push email is a method of pushing content (email in this case) over the
internet to your targeted audience.
Technically Push Mail can be defined as a 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.
Push email utilizes a mail delivery system with real-time capability to “push”
email through to the client as soon as it arrives, rather than requiring the client to
poll and collect or pull mail manually. With a push email smartphone, for example,
the client’s mailbox is constantly updated with arriving email without user
intervention. Smartphones announce new mail arrival with an alert.
4. WHAT IS A PUSH MAIL ?
Push email can be especially crucial to field reporters, stock market
businessmen, military personal and other professionals for whom time is
of the essence. A one-minute delay can make all the difference in breaking a
story, losing money, or making a crucial sale.
5. START OF PUSH MAIL
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.
BlackBerry was the first personal digital assistant (PDA) to offer push
email and gained near-instant success as a result. Today, many devices
have incorporated push email, and its popularity continues to grow. Some
of the products that have incorporated push email include Chatteremail
for Treo, Nokia Intellisync Wireless Email, Roadsync, and Sony
Ericsson phones.
6. PROTOCAL USED IN PUSH MAIL
TECHNOLOGY
The different protocols used in Push Mail technology are as follows :
RIM’s standards for BlackBerry.
Push-IMAP
SyncML
IETF Lemonade (Its an extension to IMAP and SMTP)
Microsoft Exchange 2003 standards.
7. SOME POPULAR PUSH MAIL SETUPS
Microsoft’s Direct Push
The IMAP IDLE Push
RIM BlackBerry Push
8. Microsoft’s Direct Push
The smartphone sends an HTTP request to the Exchange server, asking
to be notified when something changes on the server.
This request lasts for the shorter of (a) a timeout period and (b) a
change on the server.
If there is a change, the Exchange server responds to the smartphone
with details of the folders in which the changes have occurred.
Upon receiving this response, the smartphone sends a synchronization
request in respect of each of the folders notified by the server, and the
server delivers the details of the changes – depending on signal strength
/ connection speed.
10. Microsoft’s Direct Push
If there is no change within the timeout period, the Exchange server
sends an empty response to the smartphone.
In either case, when the smartphone receives the Exchange response, it
reissues the HTTP request – essentially, this is a looping process, and
the issue / receive loop is often referred to as the “heartbeat”.
Each heartbeat is 309 bytes, and, by default, a heartbeat is issued every
15 minutes.
11. The IMAP IDLE Push
IMAP system works by notifying the smartphone of any changes in the
folders on the server when the user is actively monitoring the server.
This only works when the mail client on the smartphone is active, and
thus notifications stop when a user stops using the mail application or
puts the smartphone away.
IMAP IDLE issues a “NOOP” (“No Operation”) 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 of any changes.
13. RIM BlackBerry Push
To receive data RIM uses a Network Operating Centre (NOC).
Here the email is forwarded to your BlackBerry by the RIM-operated
NOC only when there is email.
Only the first chunk of email is sent. The data is sent via normal UDP
packets that are encrypted at the data level.
To find out if there is a mail or not the NOC constantly polls the inbox.
Once there is a mail the NOC encrypts the data and sends it to the
device immediately where ever it is located.
In the absence of email, nothing at all happens, and your BlackBerry
behaves much like a normal mobile phone.
15. DIFFERENT PUSH MAIL
PROVIDERS
Apple iPhone and iPod Touch
Google Android
Microsoft Windows Mobile and Windows Phone
Nokia Symbian Series 60
Nokia Messaging
Research In Motion BlackBerry
SEVEN Networks
Sony Ericsson