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1 Shared mailbox not syncing

    Question

  • Hello,

    We have recently migrated to the Office365 environment and have issues with users who have multiple shared mailboxes (full access rights granted through the admin portal).

    The thing is that when someone has multiple (large) shared mailboxes (mainly mailboxes from colleagues) Outlook is very laggy and sluggish when clicking through the mailboxes and folders, the solution for this (as stated on many forums) is to check the 'Download shared folders' option (we used to have shared mailboxes in online mode) which means you cache the shared mailboxes. Now this indeed improved the performance of Outlook alot. However the problem is that one particular mailbox from a colleague is not syncing automatically. It just stops and gives a timestamp on the right bottom corner, the only way to sync it is to force click 'Update folders' (Shift + F9).

    2 mailboxes from other colleagues sync perfectly fine, same with some other regular (non-user) shared mailboxes.

    What I have tried:

    • Delete Offline-items from the mailbox and force update folders
    • Delete OST file and download all mailboxes again
    • Disabled cache mode on all mailboxes (including own mailbox)
    • Anything in online mode is just too sluggish and not workable (even the mailbox from the main user)

    Its a shame really because with the on premise exchange server (even externally hosted with VPN) we did not have this problem.

    Would be nice if anyone could help!

    Cheers


    • Edited by Youri M Monday, August 07, 2017 9:07 AM
    Monday, August 07, 2017 9:06 AM

Answers

  • We have given up on trying to get the Outlook client work, we are pushing certain users to use the Outlook Web version in the O365 portal. 

    This is currently the only way to have a workable situation.


    • Marked as answer by Youri M Wednesday, November 08, 2017 11:10 AM
    Wednesday, November 08, 2017 11:10 AM

All replies

  • Let me clear it up a bit.

    Issue 1: Slow, sluggish Outlook since Office365 migration.

    Cause: Shared mailboxes in Online mode apparently not as fast as on premises Exchange

    Solution: Caching shared mailboxes. Outlook is fast again.

    Issue 2: One shared mailbox not syncing automatically.

    Cause: Solution from Issue 1 (download shared folders enabled), other shared mailboxes sync fine.

    Solution: ?

    I hope someone can help :)


    • Edited by Youri M Wednesday, August 09, 2017 7:54 AM
    Wednesday, August 09, 2017 7:54 AM
  • Hi Youri,

    How many shared mailboxes did you open in Outlook? Generally, there might be some performance issue if you have many mailboxes opened in Outlook:

    https://support.microsoft.com/en-us/help/3136059/outlook-performance-issues-when-you-have-many-shared-folders-or-mailbo

    As stated in the article above, the number of shared folders and mailboxes that you can have open without issues depends on several factors including hardware, mailbox size, size of the shared folders or mailboxes, number of folders in a shared mailbox, item count in folders, and network speed. A computer that has slower hardware, a large mailbox and slow network connection may only be able to open 5 or fewer shared folders or mailboxes. However, a faster computer that has a smaller mailbox and a fast network connection may be able to open 10 or more shared folders or mailboxes. 

    Therefore, please try to reduce the number of shared folders or mailboxes that you have open in Outlook. You can change the configuration of the secondary Exchange mailbox to a second Exchange account in your profile. For detailed steps to do it, please refer to the Method 3 in the following article:

    https://support.microsoft.com/en-us/help/3115602/performance-problems-when-you-try-to-access-folders-in-a-secondary-mai

    Best Regards,

    Winnie Liang


    Please remember to mark the replies as answers if they help. If you have feedback for TechNet Subscriber Support, contact tnmff@microsoft.com.

    Thursday, August 10, 2017 3:28 AM
    Moderator
  • Hi Winnie,

    Thanks for your reply, my colleague has 4 shared mailboxes, all granted with full access rights through the Office365 admin portal. This exact same setup has worked perfectly before the migration to Office365.

    It bothers me that since we use Office365 shared mailboxes in Online mode cause Outlook to be extremely sluggish and laggy even though we have an 100Mbit fiberglass line that has no significant load on it what so ever.

    So the solution for the laggy Outlook was to cache the shared mailboxes which is fine to me, the workstations have enough diskspace to do this, and works fine on all but 1 mailbox which does not sync automatically.

    I am going to remove the full access rights from the particular mailbox and will add the account to Outlook and see if this solves the issue.

    I'll be back!

    Thursday, August 10, 2017 9:04 AM
  • Hi Youri,

    How about your issue currently?

    If you need any further helps, feel free to post back for more discussion :)

    Best Regards,

    Winnie Liang


    Please remember to mark the replies as answers if they help. If you have feedback for TechNet Subscriber Support, contact tnmff@microsoft.com.

    Monday, August 14, 2017 2:38 AM
    Moderator
  • Hi Winnie,

    It doesn't matter what I try, I wish online mode would just work smoothly (like it did before when we had the on-premise Exchange server hosted by a 3rd party company AND through VPN accessable) but its just really sluggish.

    There seems to be no way to get the cached shared mailbox to update like the main mailbox does.

    The only way for now is to use online mode which is nearly unworkable.

    Maybe the only way is to remove all the full access rights of each mailbox (speaking of 4 colleagues who have access to eachothers mailboxes) and add 3 extra accounts to Outlook, resulting in a main account with 3-4 extra mailboxes. Do you think that this might be a plausible solution?


    Wednesday, October 04, 2017 12:53 PM
  • We have given up on trying to get the Outlook client work, we are pushing certain users to use the Outlook Web version in the O365 portal. 

    This is currently the only way to have a workable situation.


    • Marked as answer by Youri M Wednesday, November 08, 2017 11:10 AM
    Wednesday, November 08, 2017 11:10 AM