How to Manually Delete all Sync Data from MobileMe’s Servers

From my experience, MobileMe has an inherent problem with sync data “residue.”

Most of my technical issues with the service’s calendar, contact, and bookmarks synchronization features have resulted from Apple’s cloud service not adequately cleaning up after itself. In my case, this resulted in massive event duplication in my web calendar and on my iPhone, and MobileMe would randomly sync data from months prior. In short, it was a real mess.

During a recent tech support chat with a MobileMe representative at Apple, I learned of an undocumented way to completely nuke all sync data from their servers. And it’s easy as pie.

Now this isn’t some super-secret hack of the service; it’s more of a Homer Simpson d’oh! moment. You know, sometimes you get so used to doing things in just one way and you forget to try alternatives. This is one of those cases.

Normally, to remove the computer you’re currently using from MobileMe, you’d click the “Sign Out…” button under the Account tab of the MobileMe pane in System Preferences, right here:

Mobile Me Control Panel

But this doesn’t really do much of anything. It just logs out your Mac, but leaves its mess of sync data behind.

And according to MobileMe’s support documentation, to fix a sync problem, you should simply reset your sync services folder (Mac OS X 10.5: Resetting the SyncServices folder). This works most of the time, but it only affects data on your local Mac. To truly reset your sync status, you need to purge your data from there server. But there’s no documented way to do this.

So here’s how.

First, make sure you’re working on the Mac that has the most current and up-to-date data on it.

Then make sure all your iCal and Address Book data is backed up. In iCal choose “Back up iCal…” from the File menu and save your back up file somewhere you’ll remember.

In Address Book, choose “Address Book Archive” from the Export sub-menu under the File menu (don’t ask me why both applications don’t provide the same menu structure for this identical command: yet another annoying quirk in the Mac OS). Save your Address Book archive somewhere you’ll remember. You probably won’t have to use these files, but you never know.

Click on the Sync tab of the MobileMe System Preferences pane (pictured above). Then click on “Advanced…” A sheet will drop down that displays all of the computers that are currently registered to your MobileMe account, something like this:


MobileMe Advanced Sync Sheet

Now click on each computer listed, one after another, and click the “Unregister” button. Leave the computer you’re currently using (identified as “This Computer”) until last. 

Now here’s the good part.

After you unregister the computer you’re currently using, a new sheet will drop down asking you what unused sync data you want to delete from the MobileMe servers.

MobileMe Delete Sync Data from Server

If you’ve been having problems with MobileMe sync, there’s probably all sorts of garbage that’s collected here over time (the first time I did this, it was a total mess), and I’d say just select it all and click the “Delete” button. That will completely remove every trace of sync data from the MobileMe servers. From my experience that sync detritus creates huge problems and removing it can be very effective.

After you finish that, you’ll be back at the Sync tab in the MobileMe Control Panel of System Preferences. 

Activate the check box besides “Synchronize with MobileMe:” and leave the drop down menu as “Manually.” Select the items you want to sync from the list below that. This will essentially re-register your current Mac with MobileMe (you’ll have to do this on your other computers, too).

Then click on the “Advanced…” button again and you’ll be back at the list of registered computers. 

Click the “Reset Sync Data…” button and make sure you adjust the settings like so:

MobileMe Reset Sync InfoThen click the “Replace” button. This might seem redundant after having already manually deleted everything from the MobileMe server, but my understanding is that this action sends a “signal” to your other computers to fully re-download all the fresh data from MobileMe (otherwise, they might sync some bad data back up).

After that, sync as normal.

I haven’t been able to find this information anywhere else online, so I hope that by posting it at least one other person will discover it and find it useful. I know that this manual sync-data delete process saved me weeks of headaches alone.

Let me know if it helps, or if you have any problems!

45 thoughts on “How to Manually Delete all Sync Data from MobileMe’s Servers

  1. went through a similar process with Apple a couple months back. Maybe I should set this up as a regular procedure monthly.

  2. Just tried it, but system preferences crashes right after it unregisters the last computer. Can’t figure it out. Tried it on all 3 of my machines and all 3 of them, S.P. crashes. I never get the option to delete anything.

  3. Thank you ever so much for posting this solution to a problem I’ve had for a while now. I kept meaning to get around to sorting out the mess on the server… and when I found your solution I was so pleased. I followed your advice and it’s worked seamlessly. Brilliant! ‘Smiley Face’ badge for you!

  4. Thank you so much for posting this! Worked like a charm, after other multiple attempts at fixing the iCal “inconsistent data” problem.

  5. Brilliant tips. Following your procedure has solved many attempts at solving my infuriating MobileMe duplicates and sync corruptions. Thank you so much.

  6. Thank you, thank you, thank you!
    This solved all my Mobile Me issues (I got into a multi-level mess after my MBP got a motherboard replaced (and iTunes, Mobile Me decided that was a different computer AND restoring my iPhone from a older backup at the same time).

  7. Having same problem, but don’t have a Mac…does anyone know how to purge mobile me server from a PC and laptop?

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  9. Hi,
    I tried and I’m desperate… even following these steps, no data has been delete from my mobileme calendar. That’ s a big problem… each time I change something on my ical, the OLD version as well as the NEW version is posted on my mobileme calendar. Such a pain! HELP!

  10. Still unable to get never been synced off. AND I have previously synced auto with this machine for 3 years now. your solution is also ineffective for me. I’ll search for yet another “solution”

  11. Andrew. Thanks for the post! You rock. Very easy and effective tip and totally did the trick.

    This is the best and only way I found to removing your data clean off Mobileme. [other then literally deleting those files manually from the server – something we can’t and don’t know how to do]

    IMPORTANT iPHONE USERS NOTE : if you have an iphone that is set to push/auto-sync with Mobileme as well, i strongly recommend turning off its wifi/data while you do this. Failure to do this may cause Mobileme to sync again with your iphone in-between the “delete” action and the “replace” action on this post. [and thus ‘corrupt your Mobileme ‘Cleanup’ job]

    After you complete the procedure on this post, then its safe to turn your iphone wifi/data on again. It will then re-syncs with mobile me smoothly. [I noticed it then automatically replaced the database on the iphone safely with the one from the server]

  12. Thank you. I’m keeping my fingers crossed that this solves my problem.

    Any recommendations on how I get rid of all the previous duplicates that MobileMe created? I tried iCal Dupe Deleter but it just seems to hang up my system. (Man! MobileMe has left quite a mess for me to clean up…Wish I had found your advice sooner).

  13. Thank you. I’m keeping my fingers crossed that this solves my problem.

    Any recommendations on how I get rid of all the previous duplicates that MobileMe created? I tried iCal Dupe Deleter but it just seems to hang up my system. (Man! MobileMe has left quite a mess for me to clean up…Wish I had found your advice sooner).

  14. Excellent! Simple, to the point, and a great solution – just seeing our mobileme calendar completely empty for a moment was better than seeing it with triplicates of some events and missing others!

    You have saved my job!

  15. But what if the only current and up-to-date is on my iPad/iPod, where I cannot back it up? I have a strange syncing problem, where data from my iPad and iPod synchronise perfectly, and data from Mobile Me and my iMac reach each other, but not from iPad/iPod to Mobile Me/iMac. I spent hours discussing this wit the Mobile me helpdesk and all sort of synchronisation resets have been tried with no success.

  16. Wonderful! Thanks a million — after days of frustration and hours and hours of reading and searching for solutions on the web — and complete failure from (the however friendly) Apple support folks to provide any help — I just did it in a few minutes thanks to your clear instructions. Finally I have all my calender data and addresses on both my iphone and ipad! I was starting to go mad….

  17. This looks like what I need to do — but someone who has done it, please confirm the following…

    My problems is that the only “good” copy of my calendar data is on — all the computers refuse to sync with it. The iPhone and iPad still work with so they’re up to date with the correct data, but of course that data can’t be pushed up to

    That being the case, if I do this, will I wipe out my calendar? I do NOT want to do that.. I just want to wipe out the sync data, ie make the calendar think it’s never synced anything with anyone… so that a fresh sync pushing it down to my computers would work.

    I hope that’s clear… I want to get all these devices talking, but I do not want to wipe out what’s in the cloud — it’s the only “good” data. What do I do!?

    Thanks in advance.

    • Yeah, if you follow the steps here, you’ll nuke your good data on MobileMe. This process is all about purging MobileMe when you have a good copy locally.

      It sounds like you need to reset the sync with your local machine. To do this, go to the Sync tab of the MobileMe item in System Preferences. Click on the Advanced… button, then click Reset Sync Data… Make sure the direction of the reset reads, “On this computer with sync info from MobileMe”.

      Hope that works for you.

  18. i was able to unregister and delete all old data from mobile me. and i can successfully sync my contacts. however, every-time i sync my calendar, all the old data still re-loads on mobil me. help?!?!

  19. Most of the above seems to relate to Mac users but I don’t see why it wouldn’t work for those of us on Windown XP, Windows 7 and BlackBerry Torch (that’s what I need to sync to since I upgraded from the iPhone) One BIG QUESTION – I am assuming that the MM control panel ahould be on my XP desktop only, then add the MM email address to the Win 7 laptop & the BB.

  20. This has been a big problem for me recently and had no idea how to solve it. This has worked perfectly, thanks loads!

  21. I was given these steps by tech support which solved my problem in the short term. However, this does not solve the recurring problem.

    I was told by Apple MobileMe support that if you have over 200 cumulative updates, you may have “sync issues”. MM is not a “commercial product” They recommended that I periodically go into MM preferences:advanced and “reset sync data”. You should do this when you know both your phone and mac are in sync. I am going to set up a scheduled task to do this every week or so.

    I have not been successful to get automator to record system preferences settings. If anyone has any ideas how to automate resetting sync data, let me know.
    Apparently, MM engineering do not consider this to be a product defect.

  22. In 10.6 Tried it and in the advanced pane, the question is now “stop syncing this computer” – did this , but the “would you like to delete unused sync info from MobileMe” dialogue box did not appear…..

  23. I’ve used dot mac and mobile me for years and am now ready to give it up. I don’t need, don’t want iCloud. I have a MacBookPro and use Time Machine and this works for me. I have no need to have my mail, calendar, photos, address book, docs, apps sucked up to Apple’s cloud to be pushed nowhere.

    I’ve had a gmail account for years and just been using dotmac primarily instead. So it’s time to move everything to gmail. I finally figured out how to get my address book data off of Mobile Me; and after much aggrevation moved my calendar entries to a new ‘local’ calendar – – but it did not remove the data from the mobileme server.

    My real issue is I want to get all of my mail data off of mobileme but I don’t want to nuke it on my local copy. Gmail allows me to ‘remove mail from server’ after I download it, but mobileme doesn’t seem to have this option??

    My ideal world would be iCal, Address Book and Mail client all LOCAL ONLY. I currently use the mail client with my work mail, gmail, and dotmac mail.

    I want everything off of mobile me, and as soon as I notify everyone that uses my dotmac address to use gmail, I want to nuke mobileme altogether.

    I will NOT use iCloud and i will NOT upgrade to Lion.


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  25. Fantastic, using this with John Maisey’s excellent iCal Dupe Deleter, to clear out all the synced rubbish regularly. (See Although this may all change now with the iCloud.

    This works well on OS X Lion (10.7)

  26. Pingback: Resetting MobileMe[ss] | Walt-O-Matic

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