Best Way to Remove Duplicate Contacts from a Large VCF File with 5000+ Contacts?

[Tim_David]

I manage a large contact database collected from different sources including Outlook, Gmail, and mobile devices. After combining the contact lists, I discovered thousands of duplicate entries inside my VCF file. I need a solution that can quickly detect duplicate contacts based on name, email address, or phone number and remove them without affecting unique contacts. What method would you recommend for handling duplicate contacts in large VCF files?