I am receiving a message similar to "Network HTTP Exception - HTTP 400 -"
Posted by Adam Palmer on 03 Mar 09 04:23 PM
Issue 1: This message can be displayed when registering NotifySync against a Kerio based mail server running a version earlier than 6.7, and a necessary configuration step has not been completed by the server administrator.

In order to allow your Blackberry to connect the Kerio server configuration must be edited to allow this. Either you can make this change yourself if you are responsible for the server, or request the change is made via your mail server administrator.

Please see this article for more information:

Issue 2: You have already successfully registered and have been downloading mail successfully. Then randomly during a sync process, you receive this error "Unable to synchronize account", when you select the Details button you receive the HTTP 400 error. There are currently four known causes of this problem.

Cause A:  You have attempted to perform a manual Sync whilst a scheduled Sync is in progress. Allow the scheduled Sync to complete. If this is the cause of this error, the situation will self correct once the scheduled Sync is completed, and you have selected "OK" to the onscreen prompt.

Cause B: You are in an area of poor network coverage. Sync operations are being interrupted by poor signal quality. This is particularly problem when deep within a building, such as a Cinema, Nightclub, basement etc where mobile network coverage may be minimal. Move to an area of better coverage. If this is the cause of this error, the situation will self correct once coverage quality is improved by changing location, and you have selected "OK" to the onscreen prompt.

Cause C: If you are using a Kerio or Exchange Mail Server and you have a very large number of email messages within one folder or a very large number of PIM items (in the thousands or ten thousands) is it possible that the volume of items is preventing the server from sending the items to the device. In this scenario some sort of error is occurring with the server which results in the server responding to sync requests with HTTP 400. This applies regardless of the sync range you are trying to use in NotifySync.

If using Kerio, you should make sure that you are using the latest version of Kerio Mail Server and for all mail servers also try to reduce the number of email or PIM items within a single folder by erasing old data or archiving.

Cause D: A disconnected sync session during a sync process causes a lock and primarily affects Kerio servers v6.6 and below. If this is the cause of this error, you will receive this error on screen during every sync cycle and the problem will not self correct.

It is recommended that where possible, Kerio is upgraded to a minimum of v6.7.

If you are receiving this error constantly, on every sync cycle, a workaround is to disable and enable synchronisation:

  1. Go to NotifySync inbox
  2. Press the Blackberry menu button
  3. Select Preferences
  4. Select Sync Settings.
  5. Deselect the Sync Emails Checkbox.
  6. Back out and Save changes
  7. Perform one manual Sync operation (from the NotifySync menu, select "Sync". Wait untill completed successfully.
  8. Now go back in to Sync Settings and reselect Sync Emails. Save changes and then perform another Sync.

If this resolution does not work for you, the problem may be with the calendar/contacts/tasks. In this case, please try this more comprehensive fix which also changes the "sync the past" settings.

  1. Go to your NotifySync inbox.
  2. Press the Blackberry menu button.
  3. Go to Preferences.
  4. Go to Sync Settings.
  5. Untick Sync Emails and set "Download the past:" to 1 day.
  6. Press the back button and save the changes.
  7. Go back to the NotifySync inbox
  8. Press the Blackberry Menu button
  9. Select Sync
  10. Wait for a synchronisation to complete. This may remove messages from your inbox as part of the process.
  11. Once complete, press Blackberry menu button
  12. Go to Preferences
  13. Go to Sync settings.
  14. Retick the Sync Emails box, leave "Download the past: " set to 1 day.
  15. Save and return to the NotifySync inbox.
  16. Perform another manual Sync.
  17. Verify that mails you have received today (if any) are now shown in the NotifySync inbox.
  18. If successful, go back to the Sync Settings screen and set "Download the past:" back to the original setting. Perform another manual Sync.
  19. If mail is now synchronising successfully, repeat the above process on the Calendar Account, Contacts Account and Tasks Account options under Sync Settings. Change them in turn from your name to none, save the setting, resync, go back in and change them back to your name and perform another manual Sync.


Last reviewed: 23/11/12


Help Desk Software by Kayako Fusion