How to: Get push GMail for free

Published by Steve Litchfield at 14:51 GMT, March 12th 2008

Real power users look away now - you'll have worked all this out for yourself - but I've been experimenting getting my GMail 'pushed' onto my S60 smartphone, for free. Herewith the results, comments and relevant how-to details.

[updated after comments on the original article - the auto-retrieval interval is different]

A little bit of background first, and a few notes. There's nothing special about GMail in the context of this article, except that it's highly recommended for the way it's universal, has an insanely good web interface and has bullet proof spam trapping. The key here is that GMail now supports IMAP access, but any other IMAP (Internet Message Access Protocol) email account will do just as well.

Now to 'push' email. It seems every man and his dog wants it, i.e. emails hitting your smartphone (with a beep) as soon as they're received into your mailbox. In other words, you don't have to wait the ten seconds or so to check your mail server when asking for your email in the 'old fashioned' way.

I can see the advantages of 'push' - there's no forgetting to hit 'Connect' every so often and there's the immediacy. If your business depends on you knowing something the instant someone emails you a fact, then push might be a lifesaver. And, of course, for businesses which already standardise on grown-up corporate email systems like Blackberry and Microsoft Exchange, it's easy and convenient to tie these into a dedicated email system pushing messages out to mobile devices.

But for single user, home or semi-pro use, I really can't see much point in complicating your email handling by inserting a third party provider or service between you and your mailbox. Like many people, I standardised on a single GMail account last year and have been supremely happy. There's a GMail mobile client, but it's Java-based, which means slower startup, unnecessary RAM overheads (important on some devices), and a manual 'refreshing' of your inbox.

Much better is to spot the fact that GMail added IMAP support for their mail service last year. Now, IMAP is a proper, grown-up email protocol, wherein you effectively access your remote mailbox directly, without deleting information from it (unless you want to). By comparison, standard POP3 email usually involves deleting messages from the server after access - and even when you explicitly tell your email program to leave the messages on the server they sometimes disappear anyway - at least, in my experience.

Also important is that the 'Auto-retrieve' settings for POP3 accounts in S60 Messaging bottom out at 30 minutes. So your shown mailbox  could be up to half an hour out of date, at worst case. IMAP, while connected, passes on emails instantly - true push email and with no third parties in the way.

So, what happens is that I've set up (see below) my S60 smartphone with GMail as a mailbox and set it up to grab my email automatically. I've set a nominal auto-retrieve time of 15 minutes, meaning that every 15 minutes a fresh connection to the IMAP server is made, in case the existing one has dropped out (usually because of moving out of data coverage or changing data network). Up to those 15 minutes, provided the connection is maintained, the IMAP mail server is effectively always 'on'  (idle) and messages get passed through immediately. As and when emails arrive in my GMail mailbox, they're usually on my smartphone in seconds or, at absolute worst, there 15 minutes later. It's all simple, it's elegant and it's almost free.

I say 'almost' because the one downside of IMAP access, combined with frequent retrieval, is that your data bill is going to go up. We're still only taking about a few hundred Kilobytes per day though, unless you have it set to grab whole messages, complete with attachments. With modern data tariffs being more generous, the extra data needs of this solution aren't really a problem.

Setting up 'push' GMail

Tip: you'll need to enter your GMail username (e.g. jsdkjskdjk@gmail.com) three or four times during the setup dialogs - it would save typing on your keypad if you typed this previously into Contacts or Notes (or similar), selected it and then used 'Copy' (on the Edit or hash keys) to put it into the clipboard, ready for pasting in (with the same keys) at the appropriate points in the procedure.

1. Go into 'Settings' in the GMail web interface, and click on 'Forwarding and POP/IMAP'. Down at the bottom of this page, enable IMAP and click on 'Save changes'.
    
   
    
   
2. Secondly, work through GMail's own IMAP Set-up page for S60 3rd Edition. It's important to go right through this, since both incoming and outgoing email services are encrypted and you have to get the security protocols and port numbers spot on - otherwise things simply won't work.
    
    
    
   
3. Now, still in Messaging on your smartphone, within 'Settings | Email | Mailboxes | GMail', head for 'Automatic retrieval' and enable 'Email retrieval'. There's a dialog to complete with your preferred hours of operation (you don't really need GMail being checked throughout the night, for example!), frequency (I suggest 15 minutes) and then you can back out to the Messaging home screen.
    
   

Now sit back and wait for email. Here's the proof of the pudding, showing my Nokia N95 8GB and my laptop, showing GMail's web interface, in perfect step.

One caveat to the above is that Messaging isn't as capable in some areas as the dedicated GMail Java-based client. In particular, there's no way to mark read items as 'unread', you can't apply 'stars', and so on. But the instant and automatic push-like retrieval is certainly a great tool in your armoury. Why not give it a try?

Steve Litchfield, AllAboutSymbian and the Smartphones Show, 13 March 2008

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Categories: How To
Platforms: Series 60, S60 3rd Edition

Quote:

Originally Posted by Unregistered I have one question about using this IDLE for IMAP thing though: if you do this, and you maintain a constant connection with the IMAP server, does this eat up battery life? Since you now have to keep an open connection with the cell tower. (Sorry if I didn't make this clear, I'm referring to using it on a cellular network, I guess if you keep Wi-Fi on all the time it WOULD drain your battery faster.)

Good question. I would hope that it wouldn't drain battery any faster, though wouldn't be surprised if it did. The radio has to be on anyway, and AFAIK IDLE doesn't actually transmit any data - but I'm not 100% on that. If you configure the email client to check every 5 minutes, then it *does* transmit data and so use more battery life (and money). Note that a 'connection' isn't a physical thing but a logical one - no action is required in order to keep it 'open'.

Of course, if you don't check for email automatically *and* don't use IDLE, then it'll very likely use less battery.

Here's the RFC on it. It has an interesting example session which has 'time passes' where there is no traffic :

"Example: C: A001 SELECT INBOX
S: * FLAGS (Deleted Seen)
S: * 3 EXISTS
S: * 0 RECENT
S: * OK [UIDVALIDITY 1]
S: A001 OK SELECT completed
C: A002 IDLE
S: + idling
...time passes; new mail arrives...
S: * 4 EXISTS
C: DONE
S: A002 OK IDLE terminated
...another client expunges message 2 now...
C: A003 FETCH 4 ALL
S: * 4 FETCH (...)
S: A003 OK FETCH completed
C: A004 IDLE
S: * 2 EXPUNGE
S: * 3 EXISTS
S: + idling
...time passes; another client expunges message 3...
S: * 3 EXPUNGE
S: * 2 EXISTS
...time passes; new mail arrives...
S: * 3 EXISTS
C: DONE
S: A004 OK IDLE terminated
C: A005 FETCH 3 ALL
S: * 3 FETCH (...)
S: A005 OK FETCH completed
C: A006 IDLE
"

It also (as well as Fastmail.fm's help) has a statement advising against having such short polling intervals as 5 minutes :

"The server MAY consider a client inactive if it has an IDLE command
running, and if such a server has an inactivity timeout it MAY log
the client off implicitly at the end of its timeout period. Because
of that, clients using IDLE are advised to terminate the IDLE and
re-issue it at least every 29 minutes to avoid being logged off.
This still allows a client to receive immediate mailbox updates even
though it need only "poll" at half hour intervals.
"

but it seems like it still assumes that the client has reliable and constant connectivity, which isn't the case with a mobile phone. I don't know enough about the network stack to know what parts of it can change without affecting applications using parts higher up the stack.

I'd repeat what I said earlier, that you should set the polling period to be the maximum you can live with, depending on how often your phone becomes disconnected from the internet. If your phone can keep a reliable connection, then 28 minutes is more advisable - less load on the IMAP server, less data transmission so lower cost for you and longer battery life.

It would be interesting to know what can cause a disconnect while in IDLE.

I would imagine a change in IP address would cause a disconnect.
This can happen if your IP address is dynamic (assigned by DHCP), which is the case for a lot of DSL connection, but I also imagine that all phones are set to DHCP too. It might be that it is only dependant on the public interface's IP address, which might not change if you're ISP is assigning private addresses.

I don't know what happens when your cell phone switches from tower to tower, but I hope that it would just be at the physical level and not involve any IP address changes.

If you lose touch with towers completely, that might be another issue. If you have your email client set to poll every 5 minutes, then when it fails to connect, it might well time out, resulting in the client disabling the polling (which I think Nokia's Messaging app does) and you not getting notified of any new messages until you enable it again.
If you have the polling set to longer, then perhaps it would give the physical layer longer to recover, and you can go for longer without a connection and still maintain IDLE at no cost since there's no IP traffic.

Yes, I think this is an important point - for people who use Nokia's Messaging client at least. Polling at a high frequency might be something you definitely don't want to do.

I would appreciate input from an expert on this issue. Steve, do you know of anyone?

Quote:

Originally Posted by Shane However, it does not work as nice as with my iphone for some reason.

What client are you using on your N95?

The plain fact of the matter is that all email clients are not created equal (some IMAP clients don't even support IDLE). It could be that the Apple one works better than the Nokia one. I know of several annoyances with the Nokia one (automatically disabling polling, for example) and it could certainly do with an upgrade - I hope Nokia do with with a firmware upgrade on my E90.

Personally, I've noticed less sync problems when you don't try to do things simultaneously. Use only one device at a time.

On the Nokia, of course, you can install a completely different email client - I'm sure there are many out there that some think work much better than Nokia's Messaging client. This is one advantage in the Nokia, since you can't install another email client on the iPhone (AFAIK) - or any client actually (unless it's always visible).

S60 is better than the Apple in that respect, but (from my understanding at least) Android is one step better than even S60 since you can *replace* the installed email client with a completely new one (I guess it gets unplugged rather than removed since it'll likely be in firmware). On S60, you have to have two installed, which is at least inellegant and just a little annoying. ...but Android is still alpha s/w and who knows what it'll be like on shipping devices - perhaps they (or, more likely SPs) will introduce restrictions of some sort to prevent you completely screwing up your device (resulting in high support costs, perhaps).

Quote:

Originally Posted by Unregistered davidmaxwaterma, I have tried both the built in email client on the N95 and ProfiMail. ProfiMail has more options obviously, but I still have the same issues.

Well, I doubt that the issue is inherently an N95/S60/Symbian one (though that's possible, I suppose). Perhaps the two clients do have the same problem and trying another would be good, or perhaps the problem is caused by the iPhone (did you say you have the same problems on a desktop client?).

It's a difficult problem to figure out without some serious debugging/network sniffing - have you tried that? I can't see how it'd be possible to do that with a cell connection - you might be able to get tcpdump running on S60, but good luck on an iPhone - but it should be possible with a wifi connection.

Max.

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