Make all the changes you need and tap Done in the upper right corner of the screen. If you just want to update the information of the same contact, tap on Update on the upper right corner of your screen.If you want to update the email address to a contact you already have, you can tap on Add to existing contacts and select a contact you already have. If an old contact sends you an email with a new email address, or if you want to update the current information of your contacts, you can do it easily within the Mail app.
How to update a contact with a new email address in the Mail app
Mouse over the contact and press the red delete button.Type in the email address or contact name you wish to delete.
Select the Compose button in the upper right corner.Enter your login credentials (and two-factor information if you have it set up).You can also remove suggested contacts in Mail from your Mac or PC computer. Find the old contact when the list of suggested emails appears.Tap the Write mail icon in the bottom right corner of the screen.
If you have removed an email address from your Contacts app but it still appears when you address a new email message, you can remove it with just a few clicks or taps.