I usually encounter the most unusual and typically the hardest to solve issues. This one is no different.
>I migrated a client from an old to a new Mac using the Migration Assistant. The old Mac had 3 user accounts. I only migrated one account to the new Mac for the mom.
>Everything migrated over (+/-250GB), programs, email settings, etc
>She is using Apple Mail. Only two accounts are setup which were part of the migration: the Mom and Dad. Both are setup as POP.
>Randomly, when composing and sending an email, the email appears to come from the son's email address. Furthermore, because of this when the recipient replies it goes to the Son's account.
Let me re-iterate:
>The only email accounts on Apple Mail are the Mom and Dad's
>This is a new Mac
*I verified the Mom and Dad's account are the only accounts in System Preferences > Internet Accounts
*I verified the SMTP Outbound server settings were the correct settings for @sbcglobal.net which is the Mom's email