[besson3c]

There seems to be a lot of confusion over what push email is and how it works. I admit that my understanding of it may not be 100%, which is why I thought it might be a good idea to create this thread to help fill the gaps in my understanding, as well as to inform others.

Push email is a term which I'm sure we will be hearing more about as time goes on - it seems to be a popular buzzword these days.

Prior to push email, your email client would check for email every x number of minutes and "pull" in new messages. The problem with this approach is that for mobile devices such as cell phones, it is difficult to have a real-time conversation with somebody over email like you would over Instant Message if there is no "check for new messages" button, or it requires constant clicking. Enter push email...

The IMAP spec includes a protocol called "IDLE" which allows clients to maintain their connection with the IMAP server so that the IMAP server can notify the client immediately upon receiving a new message. This provides instant messengerish sort of communication, the only qualification being that there are never any guarantees of instant email delivery at the SMTP level depending on the size of the server's queues and ability to accept and process new connections. The problem has been proper client support - popular IMAP servers such as Courier or Cyrus have supported IDLE for several years.

There are problems with maintaining constant connections to the IMAP server however. For starters, I suspect that this can drain battery life on mobile devices, increases bandwidth and demand on the server. I believe that as a means of minimizing this load, devices such as the Blackberry have included a server-side component designed to send notifications to these devices. However, I don't believe that such a component is strictly necessary providing that the client is designed to support this effectively and efficiently.

Apparently the iPhone does support push email, but only for Yahoo Mail. Some people have tried hacking their iPhones to trick their iPhones into thinking that they are talking with a Yahoo server, but I've never followed up to see if this works. I suspect that the next version of the iPhone will open up support for push email with more (or all) email services. How this will work I haven't looked into yet though, since I'm not an iPhone owner.

At any rate, one key point here is that the bottleneck so far has largely been with the various email clients out there. For some reason, OS X Mail opens up 4 (and sometimes more) IMAP connections with the server I'm using, which is not how IMAP is designed to work AFAIK. I would anticipate that reworking Mail to work more efficiently in this regard (and God knows it can use a lot of work in many other regards) might be necessary to keep battery life on the iPhones up.

Like I said, if there is anything here that is incorrect, feel free to chime in! I hope this is useful to somebody

[- - e r i k - -]

Very useful indeed. For once your nerdy knowledge provides useful in a non-argumentative situation. Thanks.

[besson3c]

Useful enough to reward me with a pointless cheap shot, nicely done!

[starman]

What was that app that came out YEARS ago that pushed news headlines to your PC?

[- - e r i k - -]

Any time, it's well deserved

[Paco500]

Originally Posted by starman 

What was that app that came out YEARS ago that pushed news headlines to your PC?

PointCast- it was a nightmare being a network admin in those days. Once it got popular, it killed the network. The company I worked for at the time had about 2500 employees- mostly in the US, and the WAN monitors at or NOC we lit up light a christmas tree. Like most companies, we ended up banning it.

But it was pretty cool.

[MacosNerd]

Its too bad that Apple missed the boat on this one, either by oversight or the technical short comings of OSX Mail. It seems ludicrous that Apple would omit a push client for their .mac but not for yahoo. I cannot speak for everyone but I know for a fact without this feature, I passed on the iPhone. Will I do so when the 3g comes out and if it also fails to have push email. Who knows, I'll burn that bridge when I get to it.

For me, I use a blackberry and I find the push email indispensable for my duties. Of course just having push email won't mean it will supplement my crackberry especially if there's no/little exchange support

[- - e r i k - -]

supplement != supplant

[besson3c]

To those people that need push email, would an IM client on your mobile device do the trick?

Just wondering...

[MacosNerd]

For me, no because I get emails from vendors, users and various others from the IT staff. Not everyone has IM and most people like to deal with email for the CYA aspect.

[Atheist]

Originally Posted by MacosNerd 

For me, no because I get emails from vendors, users and various others from the IT staff. Not everyone has IM and most people like to deal with email for the CYA aspect.

Unfortunately email has become glorified instant messaging.

[TETENAL]

So how does push e-mail work? You didn't explain that. In particular you didn't explain the technical differences to IDLE.

[turtle777]

Push-email is NOT a technical implementation, but a description of the end-goal.

There seem to be different WAYS to do this, IMAP IDLE is one of many technical implementations.

BlackBerry uses their own servers and clients to realize this.

Push e-mail - Wikipedia, the free encyclopedia

-t

[Peter]

I'm still not sure why, besides saving bandwidth, you'd want Push Email over just checking your email every 5 - 10 minutes.

[MacosNerd]

Originally Posted by Peter 

I'm still not sure why, besides saving bandwidth, you'd want Push Email over just checking your email every 5 - 10 minutes.

for me, its extremely useful, if I'm not at my desk. I'm on call for a number of servers and if I'm not in the office or at my desk. I still receive my emails on my crackberry. I don't see it being a huge need for personal emails since the bulk of my emails are business related.

[Peter]

and you need them INSTANTLY?

[MacosNerd]

Originally Posted by Peter 

and you need them INSTANTLY?

Not instantly but I do need them and if I'm not in the office how will I get them?

Edit:
Say I'm home having dinner and I get notified that the web server is down - this is done via email. How will I know if I didn't have my blackberry. I'm not about to log into work every night to see if everything is running. The same goes if there's a production issue and one of the programmers need a script run. I'll get emailed.

[turtle777]

Well, me personally, I don't need email instantly.
If it's urgent, don't sent me a friggin' email, give me a call.

I'm trying to heck emails only a couple of times a day in bulk, rather than all the time as they come in.

-t

[Peter]

I get why people want email on the move, but not on the move instantly.
You're not looking at your phone all the time so ...

[MacosNerd]

Originally Posted by Peter 

I get why people want email on the move, but not on the move instantly.
You're not looking at your phone all the time so ...

No but it vibrates when emails come in so, I know when I get an email. Since not everyone has my phone number, vendors, users, programmers etc. An email works a lot better besides an email covers your rear end a lot better then a call also. There's now an audit trail regarding a problem, or a request that if in the future someone questions it, I can reference the request.

[besson3c]

Originally Posted by MacosNerd 

Not instantly but I do need them and if I'm not in the office how will I get them?

Edit:
Say I'm home having dinner and I get notified that the web server is down - this is done via email. How will I know if I didn't have my blackberry. I'm not about to log into work every night to see if everything is running. The same goes if there's a production issue and one of the programmers need a script run. I'll get emailed.

Nagois or Xenos can send SMS messages to your cell phone, isn't this more efficient than waiting for somebody to email you?

[besson3c]

Originally Posted by MacosNerd 

No but it vibrates when emails come in so, I know when I get an email. Since not everyone has my phone number, vendors, users, programmers etc. An email works a lot better besides an email covers your rear end a lot better then a call also. There's now an audit trail regarding a problem, or a request that if in the future someone questions it, I can reference the request.

Does that mean you shouldn't have that account subscribed to any mailing lists or have cronjobs running that send you high volumes of email?

I need to have a ton of email sent to me, so unless this would only notify me of delivery to my Inbox and not a particular folder, this would annoy me... (we haven't been asked to provide push email within our group yet)

[MacosNerd]

Originally Posted by besson3c 

Does that mean you shouldn't have that account subscribed to any mailing lists or have cronjobs running that send you high volumes of email?

Definitely, those types of emails don't go to my blackberry.

[OAW]

Originally Posted by Peter 

I'm still not sure why, besides saving bandwidth, you'd want Push Email over just checking your email every 5 - 10 minutes.

Checking your email every 5 - 10 minutes ... or even every 30 minutes is a battery drain. If the server simply pushed email to your mobile device when it is received then that will allow for a significant boost to battery life.

OAW

[turtle777]

Originally Posted by OAW 

Checking your email every 5 - 10 minutes ... or even every 30 minutes is a battery drain. If the server simply pushed email to your mobile device when it is received then that will allow for a significant boost to battery life.

OAW

Are you serious ?

-t

[OAW]

Originally Posted by turtle777 

Are you serious ?

-t

Yeah I am serious. Pulling for email every 5 to 10 minutes is more expensive on battery life than if you have them pushed to you .... if you don't get a ton of emails. The longer the interval between when you pull then this benefit decreases until it's a wash. Longer still and pushing becomes more expensive. Of course, if you get tons of email then pushing becomes more expensive b/c you have to establish the connection individually for each message instead of bringing down multiple messages on a single connection.

IOW, there are scenarios where a light to moderate email user would benefit from a push email approach when it comes to battery life. Of course, there are other scenarios where push would drain the battery quite rapidly. Battery life is affected by many variables of which pull vs. push is just one. As always, YMMV.

OAW

[besson3c]

Holding a connection open can also be a battery drain, no?

[Laminar]

Originally Posted by MacosNerd 

No but it vibrates when emails come in so, I know when I get an email. Since not everyone has my phone number, vendors, users, programmers etc. An email works a lot better besides an email covers your rear end a lot better then a call also. There's now an audit trail regarding a problem, or a request that if in the future someone questions it, I can reference the request.

Someone doesn't quite get it.

[TETENAL]

Originally Posted by besson3c 

Holding a connection open can also be a battery drain, no?

On GPRS? How are SMS transmitted? They are "pushed" obviously and don't seem to drain a cell phone's batteries.

[MacosNerd]

Originally Posted by besson3c 

Nagois or Xenos can send SMS messages to your cell phone, isn't this more efficient than waiting for somebody to email you?

No, generally not. Most people I know don't use SMS (nor do I). Maybe its more effecient but if nobody uses it in the organization what good is it.

Besides, I may or may not be at my desk. Getting an email means I'll have it sitting there in my inbox, or if I wish, I can address the issue via the blackberry. Wouldn't the SMS solution be limited to only the cell phone?

[turtle777]

Originally Posted by TETENAL 

On GPRS? How are SMS transmitted? They are "pushed" obviously and don't seem to drain a cell phone's batteries.

AFAIK, push and pull are merely two different TECHNICAL implementations.

In both cases, the sender and receiver have to communicate, and communicating means data being sent AND received (handshake etc). So on battery, it should be more or less neutral.

I don't see how the receiver being in passive receive mode (push) would save battery over the receiver every now and then sending a "short "pull" signal.

Yes, one could argue that sending the "pull" signal would cost more energy than just receiving the push, but come on now, that's gotta be marginally small savings.

-t

[TETENAL]

Battery savings would have to come from the W-LAN circuit powering down and a wake signal pushed over the cell network which is on all the time anyway for a cell phone.

[turtle777]

Originally Posted by TETENAL 

Battery savings would have to come from the W-LAN circuit powering down and a wake signal pushed over the cell network which is on all the time anyway for a cell phone.

What WLAN circuitry ? I thought we were talking push and pull over the G2 / G3 phone network.

-t

[besson3c]

Originally Posted by MacosNerd 

No, generally not. Most people I know don't use SMS (nor do I). Maybe its more effecient but if nobody uses it in the organization what good is it.

Besides, I may or may not be at my desk. Getting an email means I'll have it sitting there in my inbox, or if I wish, I can address the issue via the blackberry. Wouldn't the SMS solution be limited to only the cell phone?

Huh? Everybody with a cell phone has SMS - and in this case the communication is one way, much like getting a page on a pager. So, I'm not sure what you are getting at here...

[besson3c]

Originally Posted by TETENAL 

On GPRS? How are SMS transmitted? They are "pushed" obviously and don't seem to drain a cell phone's batteries.

I don't know enough about cell phone technology to know how this works, but what I had in mind was that the cell phone wouldn't be able to "sleep" like a computer does since this would sever the constantly running connection.

Obviously there are huge gaps in my knowledge since this applies to receiving calls too, but...

[angelmb]

Is: a feature my BlackBerry has.
Isn't: free.

Am I mistaken?