I have the same contact details in my iphone xr on IOS 17
One of these contacts is the one that imessage/sms uses
The other one of these contacts is used by iphone when I send emails.
So if I delete one, I lose sms history. If I delete the other, I lose email history
Windows, Windows 10
Thanks for posting in the Apple Support Communities China888,
Providing a bit more information about what your objective is, can help members of the community provide specific and relevant guidance to help you reach that goal.
If the mean time, we recommend reviewing the following resources, which may provide some helpful insight:
• If your iCloud Contacts, Calendars, or Reminders won’t sync
Cheers!
How to fix sms and email using 2 different contacts names for same person on same iphone
