I am facing a high usage of mobile data with my mail app since yesterday.
In two days I was on mobile data for 4h each day. The result was a usage of 300MB of mobile data. I did not send/receive more than 20 emails. No major attachments.
Right now, I have no guess where this could come from. Anybody who could help?
in a months time you mean…
(and mine is not the apps total consumption, but only mobile data)
That.s also only mobile data
@harvey186 @ralxx
I hope I can reactivate this question. I experience the same problems with the very high data consumption of the mail app. I have 4 mail accounts added that should check for new messages every 10-15 minutes. This comes to a data usage of almost 1GB per month which is unnecessarily high! Also, the battery usage is almost 15%. I have the feeling that it could be caused by wrongly set settings. However, I think the synchronization frequency is reasonable?!
Edit: The WLAN data usage is 2,7GB for the mail app … also strangely high
One thing we have to make clear is: is/are the mail account(s) in Push mode or is/are it/they polling the mail server again and again? Polling a mail server can lead to high data volumes without any sense if the Inbox folder is not cleaned up and full of old and already read mails. It depends on the mail app if it also requests the mail bodies and attachments again and again.
If you are not sure how the mail app does it, clean your Inbox on the mail server and look what happens after this.
What do you mean with clean my inbox? I do not want to delete the mails but they are all marked as read/opened if I would log in into the mail account in a browser.
How can I find out whether the accounts are in push mode or polling over and over again?
I think this could really be the reason especially as I have no clue what I am doing 
So sorry for my possibly stupid questions!
Clean the Inbox means: remove all the stuff which is currently there. Delete it or move it anywhere else (this means: into another folder) but don’t let this there in the Inbox. The Inbox is not at all a good place for archiving read mails. Make an Archive folder for that on the mail server, I have some ten sub folders in my Archive. The best way to do this is using the web interface of your mail server on a real computer. Some mail apps store mail messages including attachements locally, these stored data get sometimes in disorder when you move too much around.
Push mode is a feature of the mail account(s). You must (in the mail app) open the settings of a mail account. There is a section for settings of receiving. When a mail account is in Push mode the frequency of receiving new messages from the server is typically set to “Never”. This is because the mail app receives new messages by a push from the server. Otherwise if you see there an interval of 5 minutes or so your mail app requests all these data from the mail server every five minutes. This is called polling.
The Push mode causes much less data transfer, 100kB per day or so. If your mail server(s) support(s) it you should setup each mail account for Push. It’s also much faster.
(Note: setting up a mail account for Push needs some more options than the polling frequency mentioned above.)
Ok thanks a lot for your explanations I got it now, I think. My mail accounts do have subcategories in which mails get stored automatically. I do not have a general inbox therefore I was confused.
I also checked the “receiving” settings and I think I had both ways activated, polling (which I now switched to once every day) AND also push notifications. I confirmed this by only changing the polling and then sending a test mail which got immediatly notified.
I think the mail app could help you with installing new accounts in a way that it warns you/clarifies about these two ways of checking for mails. As a user with not too much know-how I set up these mail accounts and entered my credentials and I thinkt since then both, push and polling, were automatically activated.
Anyway from now on it should work the way it should, at least for me, so thanks for helping 
Yes, that’s typical for Push, good when this works. You can now indeed set the frequency to “Never”. Even when your device is off the mail server will keep all the received messages in mind and when the device comes back it gets all them at once. You never need to poll the server again.
The mail app asks you once when you add a new mail account if you want Push support (because this depends on the mail server). And if you answer Yes polling should indeed be switched off. But, OK, the mail app doesn’t explain the difference and doesn’t keep you away from setting up something else later.
Now keep having an eye on the amount of data caused by the mail app. Should decline remarkable now.
