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dldorger's avatar
dldorger
Copper Contributor
Jun 03, 2026

Unable to sync my iPhone to my Outlook 2019 anymore

I can’t sync my Outlook 2019 calendar and contacts to my iPhone on my Lenovo Windows 11 Computer anymore.  For years I have been using iTunes to sync my phone but recently, for some unknown reason, iTunes quit recognizing my computer and all attempts to reauthorize it failed.  My research into this situation told me that Apple is phasing out iTunes in favor of Apple Devices and Apple Music.  Apple Devices does not sync my Contacts or Calendar.  Also, for some reason my Outlook Data files are .OST files instead of .PST.  I don’t know why this is because I am not on an Exchange and my Office 2019 is a stand-alone. The .OST format seems to be causing problems with any solution I have been able to find.  Even iCloud cant sync them.

Can anybody help me get my iPhone to sync my calendar and contacts because I use it all the time?

outlook for windows

1 Reply

  • RobertSparnaaij's avatar
    RobertSparnaaij
    MVP
    Jun 04, 2026

    iCloud can sync your contacts between your iPhone and Classic Outlook, but they have to be stored within the iCloud data file in Classic Outlook. It doesn't sync with your existing Contacts folder.

    Using an ost-file is normal for Exchange, Outlook.com and IMAP accounts. Pst-files are only used by POP3 accounts and archives for local storage.