GFI Software

Welcome to the GFI Software community forum! For support please open a ticket from

Home » GFI User Forums » Kerio Connect » ActiveSync Uses Way More Data than IMAP?
ActiveSync Uses Way More Data than IMAP? [message #144484] Mon, 26 November 2018 16:40 Go to next message
fishtech is currently offline  fishtech
Messages: 609
Registered: September 2010

I am on 9.2.3 (2929) on Mac OS X (10.11.6).

I have one iPhone user on an iPhone who connects via Active Sync. Over the last month stats on the user's iPhone show the Mail app has downloaded over 10GB of cellular data.

Other users who use Mail configured with IMAP have downloaded just 100 MB cellular data in the same period.

Is it expected that an Active Sync user would download so much more Mail than IMAP users?



PS. This user was also allocated a new phone recently... would ActiveSync download a bunch of Mail data for caching on the new phone?
Re: ActiveSync Uses Way More Data than IMAP? [message #144485 is a reply to message #144484] Mon, 26 November 2018 17:49 Go to previous messageGo to next message
freakinvibe is currently offline  freakinvibe
Messages: 593
Registered: April 2004
There are a lot of factors that can influence data usage in ActiveSync:

  • Sync Window (standard: 2 weeks of mails are synced). If you set that to "All", a lot of data might be transferred
  • Mailbox size, Calendar size, Number of Contacts
  • While Imap only syncs mail, Active Sync also syncs Calendar, Contacts and Tasks
  • Options: Do you only download email headers, full body and/or attachments

Dexion Services AG - IT Support Services in Basel, Switzerland

[Updated on: Mon, 26 November 2018 17:50]

Report message to a moderator

Re: ActiveSync Uses Way More Data than IMAP? [message #144492 is a reply to message #144484] Wed, 28 November 2018 02:20 Go to previous messageGo to next message
jimsky7 is currently offline  jimsky7
Messages: 21
Registered: April 2006
Location: San Francisco CA
I've experienced something like that. Took me days to debug and discover what it was. It's just "some users" not all. And in my case it's Mac ( users who have selected "Exchange" as the server type when connecting their accounts to Kerio-Connect. If they first delete each account and then re-enable it as IMAP, then the traffic flow stops. (This isn't a great solution as old emails may be deleted in user systems when the old accounts are deleted...)

(I don't know the technology of ActiveSync except that I think it exists on Exchange and not on IMAP, so that's why I'm answering you.)

In my case one user on an iMac using Apple Mail was pulling down 70GB a month (he had three "Exchange" accounts set up). His "upload" traffic was about 6mbps at all times 24/7. He was exceeding Comcast caps by 2x for a month before we discovered this. After days of fiddling we discovered a workaround...using IMAP for those accounts instead of Kerio's "Exchange" equivalent.

After switching to IMAP his monthly email usage was just a few GB and his ongoing upload traffic went to about 100kbps.

I also have iPhone users with ActiveSync turned on, but none of them have yet experienced this problem. That includes myself on an iPhone.

It was definitely -not- just downloading mail. That's the first thing one thinks of, but that's not what was happening. This was some other issue generating constant upstream traffic going out and flooding the channel. So you should certainly explore whether the users had lots of mail to download, but if you have a way to check you should look at the actual traffic flow from the device and I suspect you'll find it's ongoing and not just when mail is being downloaded.
Re: ActiveSync Uses Way More Data than IMAP? [message #144515 is a reply to message #144484] Thu, 29 November 2018 16:50 Go to previous message
Maerad is currently offline  Maerad
Messages: 275
Registered: August 2013
I also had those problems, but they were solved quickly.

In all cases, the problem was the user itself. For mobiles some had "download attachment" active every time, others synced all mails instead the standard option "last 3 days".

Some changed the kerio settings in Outlook (only 180 days with attachment to EVERYTHING). They all didn't know what they did and had the impression, to see all mails, they needed it.

Another part was, that many enabled all folders to sync in kerio client for exchange and in most cases synced "all time mail" - so every damn public folder was also synced.

Till now, I never encountered a user that didn't fuck it up himself.

Thing is, IMAP is different, because the public folders are missing, calendars etc. Also they only sync every hour instead of push. If you still have that problem, check the sync settings.
Previous Topic: Outlook 2019
Next Topic: Synchro and huge public contacts
Goto Forum:

Current Time: Thu Jun 08 02:43:49 CEST 2023

Total time taken to generate the page: 0.02305 seconds