Email "TO" & "FROM" Addresses Changed After Receiving Update

ShawmutRR wrote:

After receiving a system update, all of my incoming and outgoing emails show a completely different name in the "TO" and "FROM" fields. My email address is correct, but "TO" and "FROM" have changed. For example, my correct name was John Smith, and my email address was jsmith@123.com. Now, all email that I receive and send have the incorrect name of Mary Smith in the "TO" and "FROM" fields, but the email address of jsmith@123.com remains correct. How do I correct this issue?

MacBook Air

Version 10.15.4 Mac OS Catalina

I would make a change in your Contacts app to reflect the correct name.

Also from Mail>Preference>Viewing you can uncheck "Smart Address"

Use Smart Addresses in Mail on Mac - Apple Support

—if no resolve you can rebuild mailboxes:

Rebuild mailboxes in Mail on Mac - Apple Support