Sometimes Apple Mail will insist on providing an incorrect address for a person when you type their name, or start typing their email address, when filling in the "To" field of a new email. This is usually caused by an accidental incorrect address being used in the past, and that being remembered and re-used for future emails to the same person.
Mail stores all the email addresses of people you have sent messages to in a database called "Previous Recipients". You can edit this and remove incorrect addresses by following these steps...
In Mail: Go to the "Window" menu, and choose "Previous Recipients". Type part of the person's email address in the search area. Note: avoid typing anything which is part of the error. When you see the entry to be deleted, click it. Click the "Remove from list" button.
I usually write a blog post about once a week. The latest post can be viewed here: Avoid Microsoft: If you don't really like computers much you could make things a bit better for yourself. (posted 2024-12-04 at 12:05:50). I do podcasts too!. You can listen to my latest podcast, here: OJB's Podcast 2024-08-22 Stirring Up Trouble: Let's just get every view out there and fairly debate them..