Duplicate Contacts in Outlook (39,000 of them)

Posted on 2012-09-05
Last Modified: 2013-03-15
We have a client who is experiencing duplication of their Outlook contacts.

One user needs his contacts accessible on his iPhone and iPad, as well as Outlook and other staff use the same contact list.

The size of the contact list is 4,305. Recently it blew out to 39,000. I was able to remove the duplicate entries using a 3rd party tool.

What I would like to know is how to ascertain the cause of the duplication of emails.
I suspect it could be due to sync of multiple inboxes and devices with the one contact list.
Question by:ITtelligent
    LVL 1

    Expert Comment

    Check to see if it is outlook addons creating the problem. Additionally see if sync contacts is enabled on the Ipad device.

    Is outlook in cache or online mode? I suggest online mode for now.
    Use Outlook in Savemode and then attempt to sync and see if the issue reoccurs.
    LVL 52

    Expert Comment

    What I would like to know is how to ascertain the cause of the duplication of emails - Sorry there isnt a way or logs that will tell how the duplication happened (Its mostly the Handheld device issues when upgrading or sync with multiple accounts).

    There is another good tool to remove Duplicates OVID.

    - Rancy
    LVL 47

    Expert Comment

    Duplicate Contacts in Outlook is 99% of the time related to the sync of a mobile device to exchange

    Theres a few way this can happen

    usually the default setup on Mobiel Devices with Active Syn are set for Two way Sync
    Once the phone is synced initally, the contacts are copied over
    Next time the phone Syncs, its syncing back those contacts to exchange for the user
    Each time the sync occures the contacts are duplicated

    Another way this happens is

    The user may have already previously had contacts on their phone that are the same in their Outlook Contacts

    When the phone syncs these, contacts are added to the users contacts in Outlook/exchange

    Once you have removed all the duplicates in outlook

    You can change the SYNC to one-way to phone only
    This will stop the duplicates from happening

    Otherwise, if the user requires the two way sync

    When deleing duplicates in outlook
    Make sure they are exactly the same

    After the phone sync
    Some may just have phone numbers
    and some may be the email contacts

    Make sure there are no "Duplicates" with spelling mistakes or variations in Format such as
    Jon Doe
    Doe, Jon

    Conacts like this will get duplicated every time

    ONce you happey that outlook has all the users Outloook contacts, and all the mobile contacts that were synced from the phone...

    Go back to the mobile device
    Remove the exchange sync
    Clear the inbox, calendar, contacts ect ect

    Now re-setup the two way sync

    This will sync all the contacts from outlook back to the users phone

    User should have all the contatcs they had and the outlook contacts

    Just make sure the user is aware when updating contacts to check for existing contacts first
    If they exist edit the contacts in the phone, dont create a new one

    If they do not exist, enter it in the phone how they would in outlook

    Same goes for Outlook
    Make sure they odont add contacts in Outlook that may already exist on the phone in a different format as above
    LVL 1

    Accepted Solution

    We've narrowed it down.

    We turned on Mailbox Access Auditing and narrowed the culprit down to an iPhone. Noting high resource use by w3wp.exe too, we've narrowed this down to a known issue with some devices syncing large numbers of contacts.
    It seems there's no real fix as yet. We're culling some contacts and pinning our hopes on iOS 6.

    Featured Post

    Highfive Gives IT Their Time Back

    Highfive is so simple that setting up every meeting room takes just minutes and every employee will be able to start or join a call from any room with ease. Never be called into a meeting just to get it started again. This is how video conferencing should work!

    Join & Write a Comment

    Get an idea of what you should include in an email disclaimer with these Top 5 email disclaimer tips.
    "Migrate" an SMTP relay receive connector to a new server using info from an old server.
    The basic steps you have just learned will be implemented in this video. The basic steps are shown to configure an Exchange DAG in a live working Exchange Server Environment and manage the same (Exchange Server 2010 Software is used in a Windows Ser…
    This video discusses moving either the default database or any database to a new volume.

    731 members asked questions and received personalized solutions in the past 7 days.

    Join the community of 500,000 technology professionals and ask your questions.

    Join & Ask a Question

    Need Help in Real-Time?

    Connect with top rated Experts

    18 Experts available now in Live!

    Get 1:1 Help Now