Can push be blocked or fail on some isp networks, (not the mail host)

[beaky]

Over Christmas, I spent time at the home of a relative. I connected my nexus 10 tablet to his wifi (his ISP is SKY; the router is branded "sky SR101"; available connection speed is very high), and found the following effect. It is not present when I connect at home or via public wifi.
I have three accounts being checked periodically, one of them has push enabled.
I find that when my tablet has been closed for some time, so has been sleeping, when i wake it the account with push enabled shows a red error message with a time (seen often in the past if I have lost the connection).
This only *seems* to happen on the push enabled account.
Is there some feature of push operation that can be adversely affected by some aspect of the router or ISP?
Could this be concerned with the way android handles the wifi while sleeping, and the router's handling of that?

I should emphasise that my email is not hosted on my ISP, but on a web server run by 1und1.de. The problem only appears at one location.

Happy christmas., and thanks for a decent email app.

[Kostya Vasilyev]

Yes.

1 - Since version 4.1 (or 4.2?) Android puts WiFi hardware into low energy mode when the device is asleep. This is a special mode that has to be negotiated with the WiFi router, and on some devices, it just plain doesn't work because compatibility issues (Google blames WiFi hardware manufacturers for buggy drivers, I just don't give a damn what it is...)

2 - Irrespective of the above, some network providers are very aggressive about closing idle network connections. And IMAP IDLE connections are of course idle.

3 - A corollary to point 2: AquaMail has code to try to "ping" IMAP IDLE connections to keep them alive. Sometimes connections get closed so fast, that the app always discovers them having gone dead, and has to abort them, and connect again.

That's what I would guess from your description...

[beaky]

Yes.

1 - Since version 4.1 (or 4.2?) Android puts WiFi hardware into low energy mode when the device is asleep. This is a special mode that has to be negotiated with the WiFi router, and on some devices, it just plain doesn't work because compatibility issues (Google blames WiFi hardware manufacturers for buggy drivers, I just don't give a damn what it is...)

2 - Irrespective of the above, some network providers are very aggressive about closing idle network connections. And IMAP IDLE connections are of course idle.

3 - A corollary to point 2: AquaMail has code to try to "ping" IMAP IDLE connections to keep them alive. Sometimes connections get closed so fast, that the app always discovers them having gone dead, and has to abort them, and connect again.

That's what I would guess from your description...

That seems to fit in every respect.

Thanks.

Now all I need to do is work out whether this will stop me receiving a prearranged Skype call tomorrow. Ho hum........